UV steralizer

[Christopher]

is it wise to run the UV steralizer 24 hours a day? assuming that you only
desire a 99.9% steralization rate you don't have to run the steralizer that
much (depending upon gph through the steralizer and tank size). I've read:

9.2 * (tank size / gph through steralizer) = hours a day UV steralizer must
be on to attain 99.9% steralization rate (assuming uniform mixing). This
said my calculation is at most 7 hours a day, should I just run it for 8
hours a day and save my bulb life and power bill?

Should I run it 24 hours a day to achieve 99.999% steralization or for 8
hours a day?

[James Thompson]

Along these lines, I would like to know if anyone has diy ozone generator?
maybe big enough to use on swimming pool also. Any electronics techs out
there with ideas? I am also a tech.

As to you chris, why run it 24 hours, would eat the bulbs fast that way.
And not do any better job. Best to check manufacturer's recommendations.
Just my thoughts :)

"Christopher" > wrote in message
rthlink.net...
> is it wise to run the UV steralizer 24 hours a day? assuming that you only
> desire a 99.9% steralization rate you don't have to run the steralizer
that
> much (depending upon gph through the steralizer and tank size). I've
read:
>
> 9.2 * (tank size / gph through steralizer) = hours a day UV steralizer
must
> be on to attain 99.9% steralization rate (assuming uniform mixing). This
> said my calculation is at most 7 hours a day, should I just run it for 8
> hours a day and save my bulb life and power bill?
>
> Should I run it 24 hours a day to achieve 99.999% steralization or for 8
> hours a day?
>
>

[m.dekort]

The bulb life will go way down if you turn it off and on

Christopher wrote:

>is it wise to run the UV sterilizer 24 hours a day? assuming that you only
>desire a 99.9% sterilization rate you don't have to run the sterilizer that
>much (depending upon gph through the sterilizer and tank size). I've read:
>
> 9.2 * (tank size / gph through sterilizer) = hours a day UV sterilizer must
>be on to attain 99.9% sterilization rate (assuming uniform mixing). This
>said my calculation is at most 7 hours a day, should I just run it for 8
>hours a day and save my bulb life and power bill?
>
>Should I run it 24 hours a day to achieve 99.999% sterilization or for 8
>hours a day?
>
>
>
>

[Christopher]

the manufacturer has no recommended run time
double helix 36W

"James Thompson" > wrote in message
t...
> Along these lines, I would like to know if anyone has diy ozone generator?
> maybe big enough to use on swimming pool also. Any electronics techs out
> there with ideas? I am also a tech.
>
> As to you chris, why run it 24 hours, would eat the bulbs fast that way.
> And not do any better job. Best to check manufacturer's recommendations.
> Just my thoughts :)
>
> "Christopher" > wrote in message
> rthlink.net...
> > is it wise to run the UV steralizer 24 hours a day? assuming that you
only
> > desire a 99.9% steralization rate you don't have to run the steralizer
> that
> > much (depending upon gph through the steralizer and tank size). I've
> read:
> >
> > 9.2 * (tank size / gph through steralizer) = hours a day UV steralizer
> must
> > be on to attain 99.9% steralization rate (assuming uniform mixing).
This
> > said my calculation is at most 7 hours a day, should I just run it for 8
> > hours a day and save my bulb life and power bill?
> >
> > Should I run it 24 hours a day to achieve 99.999% steralization or for 8
> > hours a day?
> >
> >
>
>
>

[Christopher]

is turning it on and off once a day that bad for it? I would think the fact
that I would be running it for 1/3 of the time would outweigh the shortening
of life from the on/off cycles (I would just put it on a timer after all).

"m.dekort" > wrote in message
...
> The bulb life will go way down if you turn it off and on
>
> Christopher wrote:
>
> >is it wise to run the UV sterilizer 24 hours a day? assuming that you
only
> >desire a 99.9% sterilization rate you don't have to run the sterilizer
that
> >much (depending upon gph through the sterilizer and tank size). I've
read:
> >
> > 9.2 * (tank size / gph through sterilizer) = hours a day UV sterilizer
must
> >be on to attain 99.9% sterilization rate (assuming uniform mixing). This
> >said my calculation is at most 7 hours a day, should I just run it for 8
> >hours a day and save my bulb life and power bill?
> >
> >Should I run it 24 hours a day to achieve 99.999% sterilization or for 8
> >hours a day?
> >
> >
> >
> >
>
>

[Bob]

http://www.aquasite.com/knowledge/tips/ozone_reactor.shtml


"James Thompson" > wrote in message
t...
> Along these lines, I would like to know if anyone has diy ozone generator?
> maybe big enough to use on swimming pool also. Any electronics techs out
> there with ideas? I am also a tech.
>
> As to you chris, why run it 24 hours, would eat the bulbs fast that way.
> And not do any better job. Best to check manufacturer's recommendations.
> Just my thoughts :)
>
> "Christopher" > wrote in message
> rthlink.net...
> > is it wise to run the UV steralizer 24 hours a day? assuming that you
only
> > desire a 99.9% steralization rate you don't have to run the steralizer
> that
> > much (depending upon gph through the steralizer and tank size). I've
> read:
> >
> > 9.2 * (tank size / gph through steralizer) = hours a day UV steralizer
> must
> > be on to attain 99.9% steralization rate (assuming uniform mixing).
This
> > said my calculation is at most 7 hours a day, should I just run it for 8
> > hours a day and save my bulb life and power bill?
> >
> > Should I run it 24 hours a day to achieve 99.999% steralization or for 8
> > hours a day?
> >
> >
>
>

[Sam Hopkins]

Is a $20 bulb every year really worth it? Run it 24 hours a day.


"Christopher" > wrote in message
rthlink.net...
> is it wise to run the UV steralizer 24 hours a day? assuming that you only
> desire a 99.9% steralization rate you don't have to run the steralizer
that
> much (depending upon gph through the steralizer and tank size). I've
read:
>
> 9.2 * (tank size / gph through steralizer) = hours a day UV steralizer
must
> be on to attain 99.9% steralization rate (assuming uniform mixing). This
> said my calculation is at most 7 hours a day, should I just run it for 8
> hours a day and save my bulb life and power bill?
>
> Should I run it 24 hours a day to achieve 99.999% steralization or for 8
> hours a day?
>
>

[Bruce Geist]

Actually, the 9.2 factor will give you 99.99 % throughput through the
sterilizer. To get 99.9% throughput, the factor is 6.9.
See http://www.wideopenwest.com/~brucegeist/turnover/index.html
for details.

One strategy is to set the flow rate through the sterilizer so that one pass
kills target organisms you wish to kill. If you set the flow rate slow
enough that everything you want to kill is killed, then run your sterilizer
long enough to "turnover" the tank water once or twice a day,
and then shut the sterilizer off.

Basically, the more slowly you put water through the sterilizer, the more UV
exposure every bit of water passing through the sterilizer receives. If
you have a 36 watt sterilizer with about a 3 inch diameter chamber for the
water, and your flow rate is about 100 gallons per hour, then you are
probably irradiating your water at about a 100 microwatt-seconds dose, which
is
enough to kill most bacteria, algae, and many protozoa. (This is only a
crude estimate; I am working on developing some assessment tools on my
website which will provide more specific advice..) If you are using a lower
wattage sterilizer, or a lower diameter sterilizer, then your flow rate will
need to be lower still to achieve the same dose.

In the article I wrote cited above, I show that when you have run 99.9% of
the water through the sterilizer at least one time, in actuality 99.2% of
water has passed through 2 or more times, and 96.8% will have passed through
the sterilizer 3 or more times! I recommend 6.9*(tank size in
gallons)/(flow rate in gallons) to be your target turnover time. If your
flow rate is chosen with some care, you need not run your sterilizer all
the time. You will save bulb life by running your sterilizer through only
one or two
turn-over intervals per day.

I hope you enjoy the article on turnover time; this is the first time I have
published the web address. Remember that you can skip to the conclusion
and get the formula to use. I am in process of collecting data for a suite
of articles on the topic UV sterilizers. Be watching this news group or my
web site; I am waiting on data from a manufacturer. -Bruce Geist

"Christopher" > wrote in message
rthlink.net...
> is it wise to run the UV steralizer 24 hours a day? assuming that you only
> desire a 99.9% steralization rate you don't have to run the steralizer
that
> much (depending upon gph through the steralizer and tank size). I've
read:
>
> 9.2 * (tank size / gph through steralizer) = hours a day UV steralizer
must
> be on to attain 99.9% steralization rate (assuming uniform mixing). This
> said my calculation is at most 7 hours a day, should I just run it for 8
> hours a day and save my bulb life and power bill?
>
> Should I run it 24 hours a day to achieve 99.999% steralization or for 8
> hours a day?
>
>

[Donald Kerns]

NETMAX alert. Grab this URL guy!

-Donald

Bruce Geist wrote:

>
> Actually, the 9.2 factor will give you 99.99 % throughput through the
> sterilizer. To get 99.9% throughput, the factor is 6.9.
> See http://www.wideopenwest.com/~brucegeist/turnover/index.html
> for details.
>
> One strategy is to set the flow rate through the sterilizer so that one
> pass
> kills target organisms you wish to kill. If you set the flow rate slow
> enough that everything you want to kill is killed, then run your
> sterilizer long enough to "turnover" the tank water once or twice a day,
> and then shut the sterilizer off.
<snip good stuff>

> I hope you enjoy the article on turnover time; this is the first time I
> have
> published the web address. Remember that you can skip to the conclusion
> and get the formula to use. I am in process of collecting data for a
> suite
> of articles on the topic UV sterilizers. Be watching this news group or
> my
> web site; I am waiting on data from a manufacturer. -Bruce Geist
>

--
"When you've lost your ability to laugh, you've lost your ability to think
straight." -To Inherit the Wind

[willis stanley]

Thanks much for the info! Precisely what I needed to read.

In article >,
says...
>
> Actually, the 9.2 factor will give you 99.99 % throughput through the
> sterilizer. To get 99.9% throughput, the factor is 6.9.
> See http://www.wideopenwest.com/~brucegeist/turnover/index.html
> for details.
>
> One strategy is to set the flow rate through the sterilizer so that one pass
> kills target organisms you wish to kill. If you set the flow rate slow
> enough that everything you want to kill is killed, then run your sterilizer
> long enough to "turnover" the tank water once or twice a day,
> and then shut the sterilizer off.
>
> Basically, the more slowly you put water through the sterilizer, the more UV
> exposure every bit of water passing through the sterilizer receives. If
> you have a 36 watt sterilizer with about a 3 inch diameter chamber for the
> water, and your flow rate is about 100 gallons per hour, then you are
> probably irradiating your water at about a 100 microwatt-seconds dose, which
> is
> enough to kill most bacteria, algae, and many protozoa. (This is only a
> crude estimate; I am working on developing some assessment tools on my
> website which will provide more specific advice..) If you are using a lower
> wattage sterilizer, or a lower diameter sterilizer, then your flow rate will
> need to be lower still to achieve the same dose.
>
> In the article I wrote cited above, I show that when you have run 99.9% of
> the water through the sterilizer at least one time, in actuality 99.2% of
> water has passed through 2 or more times, and 96.8% will have passed through
> the sterilizer 3 or more times! I recommend 6.9*(tank size in
> gallons)/(flow rate in gallons) to be your target turnover time. If your
> flow rate is chosen with some care, you need not run your sterilizer all
> the time. You will save bulb life by running your sterilizer through only
> one or two
> turn-over intervals per day.
>
> I hope you enjoy the article on turnover time; this is the first time I have
> published the web address. Remember that you can skip to the conclusion
> and get the formula to use. I am in process of collecting data for a suite
> of articles on the topic UV sterilizers. Be watching this news group or my
> web site; I am waiting on data from a manufacturer. -Bruce Geist
>
> "Christopher" > wrote in message
> rthlink.net...
> > is it wise to run the UV steralizer 24 hours a day? assuming that you only
> > desire a 99.9% steralization rate you don't have to run the steralizer
> that
> > much (depending upon gph through the steralizer and tank size). I've
> read:
> >
> > 9.2 * (tank size / gph through steralizer) = hours a day UV steralizer
> must

[Christopher]

Thats a very detailed explanation, THANKS!
have a couple questions though:
if the primary reason I'm using the steralizer is to kill algae spores so my
tank stays clean is it smart to only have the steralizer running for X hours
a day? Cant the spores be released and land and settle on the glass and
leaves during the off period? My second question is how much life of the
bulb is saved when you run it for 8 hours a day? I know that the turning on
of the bulb takes away from bulb life, but would the fact that its only run
for 1/3 of the time save bulb life in the long term? I am concerned since
36W PC florescents are $50 (not exactly cheap)

"Bruce Geist" > wrote in message
...
>
> Actually, the 9.2 factor will give you 99.99 % throughput through the
> sterilizer. To get 99.9% throughput, the factor is 6.9.
> See http://www.wideopenwest.com/~brucegeist/turnover/index.html
> for details.
>
> One strategy is to set the flow rate through the sterilizer so that one
pass
> kills target organisms you wish to kill. If you set the flow rate slow
> enough that everything you want to kill is killed, then run your
sterilizer
> long enough to "turnover" the tank water once or twice a day,
> and then shut the sterilizer off.
>
> Basically, the more slowly you put water through the sterilizer, the more
UV
> exposure every bit of water passing through the sterilizer receives.
If
> you have a 36 watt sterilizer with about a 3 inch diameter chamber for the
> water, and your flow rate is about 100 gallons per hour, then you are
> probably irradiating your water at about a 100 microwatt-seconds dose,
which
> is
> enough to kill most bacteria, algae, and many protozoa. (This is only a
> crude estimate; I am working on developing some assessment tools on my
> website which will provide more specific advice..) If you are using a
lower
> wattage sterilizer, or a lower diameter sterilizer, then your flow rate
will
> need to be lower still to achieve the same dose.
>
> In the article I wrote cited above, I show that when you have run 99.9% of
> the water through the sterilizer at least one time, in actuality 99.2% of
> water has passed through 2 or more times, and 96.8% will have passed
through
> the sterilizer 3 or more times! I recommend 6.9*(tank size in
> gallons)/(flow rate in gallons) to be your target turnover time. If your
> flow rate is chosen with some care, you need not run your sterilizer all
> the time. You will save bulb life by running your sterilizer through only
> one or two
> turn-over intervals per day.
>
> I hope you enjoy the article on turnover time; this is the first time I
have
> published the web address. Remember that you can skip to the conclusion
> and get the formula to use. I am in process of collecting data for a
suite
> of articles on the topic UV sterilizers. Be watching this news group or
my
> web site; I am waiting on data from a manufacturer. -Bruce Geist
>
> "Christopher" > wrote in message
> rthlink.net...
> > is it wise to run the UV steralizer 24 hours a day? assuming that you
only
> > desire a 99.9% steralization rate you don't have to run the steralizer
> that
> > much (depending upon gph through the steralizer and tank size). I've
> read:
> >
> > 9.2 * (tank size / gph through steralizer) = hours a day UV steralizer
> must
> > be on to attain 99.9% steralization rate (assuming uniform mixing).
This
> > said my calculation is at most 7 hours a day, should I just run it for 8
> > hours a day and save my bulb life and power bill?
> >
> > Should I run it 24 hours a day to achieve 99.999% steralization or for 8
> > hours a day?
> >
> >
>
>
>

[Bruce Geist]

Basically, you are only culling the population of algae spores and bacteria
to a level, presumably, that is more like an open stream or lake. All tank
water is never sterile at any one moment in time, since algae and bacteria
are constantly re-growing.

To control a specific organism or class of organisms, use the lowest lethal
dose for that organism or class of organism, meaning you turn your flow rate
up so that water passing though is exposed to the right level of radiation,
and no more. That way, you are killing algae at the quickest possible
rate. The flow rate is effectively your control on the dosage you are
delivering. So, if algae is your target, I'd turn your flow rate to about
200 gallons per hour. This will deliver (I am estimating here) about 50,000
micro watt-seconds / cm^2 of radiation to the water passing through your
sterilizer.

Here is the shaky part; I am not sure exactly what dose will kill all algae.
So be aware, I am making a swag here. I do know that Chlorella Vulgaris, a
kind of algae, is killed by 45,000 micro watt-seconds / cm^2 of UV.
Therefore, I am recommending a flow rate that I believe will cause your 36
watt sterilizer to deliver the 50 K micro watt-seconds / cm^2 dosage. I do
not actually have intensity data for your particular sterilizer, though I
have requested it from the manufacturer (because I am doing some
mathematical modeling for an article I am writing..) I have intensity data
for a 30 and 64 watt UV set-up, so I am interpolating a result here.
However, the dosage estimate is really an estimate! Sorry I cannot be more
precise.

Now its your choice whether to leave on the sterilizer or cycle it. I do
not believe the statement that cycling a UV lamp shortens its life
significantly. Maybe it does, but I find it hard to believe. In fact, the
lamp manufacturer defines its useful life in terms of hours on, not number
of cycles. If you leave the thing on all the time, the lamp will last about
6 months. If you use it only during the day, my expectation is that it will
last a year. Since your target is algae, maybe its enough to sterilize when
the algae is multiplying during your tank's lighted period.

Do some experiments, and see if you perceive a difference in water quality
and/or algae proliferation when cycling and not cycling. And then let me
know what you conclude! I'd really like to know what your experience turns
out to be...

-Bruce

http://www.wideopenwest.com/~brucegeist

"Christopher" > wrote in message
rthlink.net...
> Thats a very detailed explanation, THANKS!
> have a couple questions though:
> if the primary reason I'm using the steralizer is to kill algae spores so
my
> tank stays clean is it smart to only have the steralizer running for X
hours
> a day? Cant the spores be released and land and settle on the glass and
> leaves during the off period? My second question is how much life of the
> bulb is saved when you run it for 8 hours a day? I know that the turning
on
> of the bulb takes away from bulb life, but would the fact that its only
run
> for 1/3 of the time save bulb life in the long term? I am concerned since
> 36W PC florescents are $50 (not exactly cheap)
>
> "Bruce Geist" > wrote in message
> ...
> >
> > Actually, the 9.2 factor will give you 99.99 % throughput through the
> > sterilizer. To get 99.9% throughput, the factor is 6.9.
> > See http://www.wideopenwest.com/~brucegeist/turnover/index.html
> > for details.
> >
> > One strategy is to set the flow rate through the sterilizer so that one
> pass
> > kills target organisms you wish to kill. If you set the flow rate slow
> > enough that everything you want to kill is killed, then run your
> sterilizer
> > long enough to "turnover" the tank water once or twice a day,
> > and then shut the sterilizer off.
> >
> > Basically, the more slowly you put water through the sterilizer, the
more
> UV
> > exposure every bit of water passing through the sterilizer receives.
> If
> > you have a 36 watt sterilizer with about a 3 inch diameter chamber for
the
> > water, and your flow rate is about 100 gallons per hour, then you are
> > probably irradiating your water at about a 100 microwatt-seconds dose,
> which
> > is
> > enough to kill most bacteria, algae, and many protozoa. (This is only a
> > crude estimate; I am working on developing some assessment tools on my
> > website which will provide more specific advice..) If you are using a
> lower
> > wattage sterilizer, or a lower diameter sterilizer, then your flow rate
> will
> > need to be lower still to achieve the same dose.
> >
> > In the article I wrote cited above, I show that when you have run 99.9%
of
> > the water through the sterilizer at least one time, in actuality 99.2%
of
> > water has passed through 2 or more times, and 96.8% will have passed
> through
> > the sterilizer 3 or more times! I recommend 6.9*(tank size in
> > gallons)/(flow rate in gallons) to be your target turnover time. If
your
> > flow rate is chosen with some care, you need not run your sterilizer all
> > the time. You will save bulb life by running your sterilizer through
only
> > one or two
> > turn-over intervals per day.
> >
> > I hope you enjoy the article on turnover time; this is the first time I
> have
> > published the web address. Remember that you can skip to the conclusion
> > and get the formula to use. I am in process of collecting data for a
> suite
> > of articles on the topic UV sterilizers. Be watching this news group or
> my
> > web site; I am waiting on data from a manufacturer. -Bruce Geist
> >
> > "Christopher" > wrote in message
> > rthlink.net...
> > > is it wise to run the UV steralizer 24 hours a day? assuming that you
> only
> > > desire a 99.9% steralization rate you don't have to run the steralizer
> > that
> > > much (depending upon gph through the steralizer and tank size). I've
> > read:
> > >
> > > 9.2 * (tank size / gph through steralizer) = hours a day UV
steralizer
> > must
> > > be on to attain 99.9% steralization rate (assuming uniform mixing).
> This
> > > said my calculation is at most 7 hours a day, should I just run it for
8
> > > hours a day and save my bulb life and power bill?
> > >
> > > Should I run it 24 hours a day to achieve 99.999% steralization or for
8
> > > hours a day?
> > >
> > >
> >
> >
> >
>
>

[Bruce Geist]

I noticed after I posted that Chlorella Vugaris, a kind of algae,
is actually killed with a dose of 22,000 micro-watt-seconds/cm^2.

If you assume most all algae is killed with a 30,000 unit dose,
you will in fact want to increase the flow rate on your sterilizer further,
to 250 or 300 gallons per hour. -Bruce


"Bruce Geist" > wrote in message
...
> Basically, you are only culling the population of algae spores and
bacteria
> to a level, presumably, that is more like an open stream or lake. All
tank
> water is never sterile at any one moment in time, since algae and bacteria
> are constantly re-growing.
>
> To control a specific organism or class of organisms, use the lowest
lethal
> dose for that organism or class of organism, meaning you turn your flow
rate
> up so that water passing though is exposed to the right level of
radiation,
> and no more. That way, you are killing algae at the quickest possible
> rate. The flow rate is effectively your control on the dosage you are
> delivering. So, if algae is your target, I'd turn your flow rate to about
> 200 gallons per hour. This will deliver (I am estimating here) about
50,000
> micro watt-seconds / cm^2 of radiation to the water passing through your
> sterilizer.
>
> Here is the shaky part; I am not sure exactly what dose will kill all
algae.
> So be aware, I am making a swag here. I do know that Chlorella Vulgaris,
a
> kind of algae, is killed by 45,000 micro watt-seconds / cm^2 of UV.
> Therefore, I am recommending a flow rate that I believe will cause your
36
> watt sterilizer to deliver the 50 K micro watt-seconds / cm^2 dosage. I
do
> not actually have intensity data for your particular sterilizer, though I
> have requested it from the manufacturer (because I am doing some
> mathematical modeling for an article I am writing..) I have intensity
data
> for a 30 and 64 watt UV set-up, so I am interpolating a result here.
> However, the dosage estimate is really an estimate! Sorry I cannot be
more
> precise.
>
> Now its your choice whether to leave on the sterilizer or cycle it. I do
> not believe the statement that cycling a UV lamp shortens its life
> significantly. Maybe it does, but I find it hard to believe. In fact,
the
> lamp manufacturer defines its useful life in terms of hours on, not number
> of cycles. If you leave the thing on all the time, the lamp will last
about
> 6 months. If you use it only during the day, my expectation is that it
will
> last a year. Since your target is algae, maybe its enough to sterilize
when
> the algae is multiplying during your tank's lighted period.
>
> Do some experiments, and see if you perceive a difference in water quality
> and/or algae proliferation when cycling and not cycling. And then let me
> know what you conclude! I'd really like to know what your experience
turns
> out to be...
>
> -Bruce
>
> http://www.wideopenwest.com/~brucegeist
>
> "Christopher" > wrote in message
> rthlink.net...
> > Thats a very detailed explanation, THANKS!
> > have a couple questions though:
> > if the primary reason I'm using the steralizer is to kill algae spores
so
> my
> > tank stays clean is it smart to only have the steralizer running for X
> hours
> > a day? Cant the spores be released and land and settle on the glass and
> > leaves during the off period? My second question is how much life of
the
> > bulb is saved when you run it for 8 hours a day? I know that the turning
> on
> > of the bulb takes away from bulb life, but would the fact that its only
> run
> > for 1/3 of the time save bulb life in the long term? I am concerned
since
> > 36W PC florescents are $50 (not exactly cheap)
> >
> > "Bruce Geist" > wrote in message
> > ...
> > >
> > > Actually, the 9.2 factor will give you 99.99 % throughput through the
> > > sterilizer. To get 99.9% throughput, the factor is 6.9.
> > > See http://www.wideopenwest.com/~brucegeist/turnover/index.html
> > > for details.
> > >
> > > One strategy is to set the flow rate through the sterilizer so that
one
> > pass
> > > kills target organisms you wish to kill. If you set the flow rate
slow
> > > enough that everything you want to kill is killed, then run your
> > sterilizer
> > > long enough to "turnover" the tank water once or twice a day,
> > > and then shut the sterilizer off.
> > >
> > > Basically, the more slowly you put water through the sterilizer, the
> more
> > UV
> > > exposure every bit of water passing through the sterilizer receives.
> > If
> > > you have a 36 watt sterilizer with about a 3 inch diameter chamber for
> the
> > > water, and your flow rate is about 100 gallons per hour, then you are
> > > probably irradiating your water at about a 100 microwatt-seconds dose,
> > which
> > > is
> > > enough to kill most bacteria, algae, and many protozoa. (This is only
a
> > > crude estimate; I am working on developing some assessment tools on my
> > > website which will provide more specific advice..) If you are using a
> > lower
> > > wattage sterilizer, or a lower diameter sterilizer, then your flow
rate
> > will
> > > need to be lower still to achieve the same dose.
> > >
> > > In the article I wrote cited above, I show that when you have run
99.9%
> of
> > > the water through the sterilizer at least one time, in actuality 99.2%
> of
> > > water has passed through 2 or more times, and 96.8% will have passed
> > through
> > > the sterilizer 3 or more times! I recommend 6.9*(tank size in
> > > gallons)/(flow rate in gallons) to be your target turnover time. If
> your
> > > flow rate is chosen with some care, you need not run your sterilizer
all
> > > the time. You will save bulb life by running your sterilizer through
> only
> > > one or two
> > > turn-over intervals per day.
> > >
> > > I hope you enjoy the article on turnover time; this is the first time
I
> > have
> > > published the web address. Remember that you can skip to the
conclusion
> > > and get the formula to use. I am in process of collecting data for a
> > suite
> > > of articles on the topic UV sterilizers. Be watching this news group
or
> > my
> > > web site; I am waiting on data from a manufacturer. -Bruce Geist
> > >
> > > "Christopher" > wrote in message
> > > rthlink.net...
> > > > is it wise to run the UV steralizer 24 hours a day? assuming that
you
> > only
> > > > desire a 99.9% steralization rate you don't have to run the
steralizer
> > > that
> > > > much (depending upon gph through the steralizer and tank size).
I've
> > > read:
> > > >
> > > > 9.2 * (tank size / gph through steralizer) = hours a day UV
> steralizer
> > > must
> > > > be on to attain 99.9% steralization rate (assuming uniform mixing).
> > This
> > > > said my calculation is at most 7 hours a day, should I just run it
for
> 8
> > > > hours a day and save my bulb life and power bill?
> > > >
> > > > Should I run it 24 hours a day to achieve 99.999% steralization or
for
> 8
> > > > hours a day?
> > > >
> > > >
> > >
> > >
> > >
> >
> >
>
>

[Bruce Geist]

I am not certain at all about when algae will bloom, or when the best time
to kill algae would be. 24/7 sounds like a good, if slightly more expensive
way to go, since you want to be sure. If you do do some experimenting, let
me know what you find.

As I said in the earlier post, I am convinced that you will kill the most
algae by tuning your flow rate to deliver the correct kill dose for algae --
about 30,000 micro-watts -sec / cm^2, and no more or less, regardless of
whether you leave your sterilizer on 24/7 or not. This will kill the most
algae, because the flow rate is highest without being too high to do kill
algae. For your sterilizer, I would say 250 to 300 gallons per hour is what
you want to flow through the sterilizer.

Good luck. BTW, I saw Leigh's post. In my opinion, Leigh is right, you
will need to do all the other algae control measures that you see discussed
in this (rec.aquaria.freshwater.plants) newsgroup. Maintain proper growth
nutrients for higher plants, get algae eating fish, maintain water quality,
etc. I use a sterilizer in my tank, but did not for the first couple of
years that I had my tank up and running. With a sterilizer, I notice clearer
water, and possibly slightly less algae buildup on the tank walls. (But I
still have to do a significant weekly cleaning..) I have seen a reduction
of surface scum, and a marked reduction in cyano bacteria (blue-green
algae), a particularly nasty smelling algae. I used to get small colonies
near my filter return and sometimes near the interface between gravel and
glass. It never spread. (The small colonies seemed to occur regardless
of my nitrate levels. I have seen insufficient nitrate levels blamed for
cyano bacteria.) Now I see very little blue green algae in my tank. I am
hoping I will never see Ick in my tank again, but at this point I make no
declarations. We'll see.

-Bruce

"Christopher" > wrote in message
rthlink.net...
> the thing is if one dose doesn't kill the algae spores then the second
dose
> probably will (since it would get another dose roughly every hour), and in
> the meantime it will be very weakened.
>
> How certain are you that algae release their spores into the water during
> the day? I know for most people it isn't a big deal but I don't like
algae
> in my tank and for me...having a steralizer seriously retard the spread of
> algae is worth it. That way I can run the lights more than 8 hours a day
> and I don't have to spend an hour scraping the sides of the tank every
other
> week. I might just leave it at that and run the steralizer 24/7 unless
you
> are fairly certain that I can time it to the release of algae spores.
Since
> the whole purpose of this purchase was to severely minimize the amount of
> work I have to put into the tank I want to have the maximum algae
> retardation possibile.
>
> "Bruce Geist" > wrote in message
> ...
> > I noticed after I posted that Chlorella Vugaris, a kind of algae,
> > is actually killed with a dose of 22,000 micro-watt-seconds/cm^2.
> >
> > If you assume most all algae is killed with a 30,000 unit dose,
> > you will in fact want to increase the flow rate on your sterilizer
> further,
> > to 250 or 300 gallons per hour. -Bruce
> >
> >
> > "Bruce Geist" > wrote in message
> > ...
> > > Basically, you are only culling the population of algae spores and
> > bacteria
> > > to a level, presumably, that is more like an open stream or lake.
All
> > tank
> > > water is never sterile at any one moment in time, since algae and
> bacteria
> > > are constantly re-growing.
> > >
> > > To control a specific organism or class of organisms, use the lowest
> > lethal
> > > dose for that organism or class of organism, meaning you turn your
flow
> > rate
> > > up so that water passing though is exposed to the right level of
> > radiation,
> > > and no more. That way, you are killing algae at the quickest possible
> > > rate. The flow rate is effectively your control on the dosage you
are
> > > delivering. So, if algae is your target, I'd turn your flow rate to
> about
> > > 200 gallons per hour. This will deliver (I am estimating here) about
> > 50,000
> > > micro watt-seconds / cm^2 of radiation to the water passing through
your
> > > sterilizer.
> > >
> > > Here is the shaky part; I am not sure exactly what dose will kill all
> > algae.
> > > So be aware, I am making a swag here. I do know that Chlorella
> Vulgaris,
> > a
> > > kind of algae, is killed by 45,000 micro watt-seconds / cm^2 of UV.
> > > Therefore, I am recommending a flow rate that I believe will cause
your
> > 36
> > > watt sterilizer to deliver the 50 K micro watt-seconds / cm^2 dosage.
I
> > do
> > > not actually have intensity data for your particular sterilizer,
though
> I
> > > have requested it from the manufacturer (because I am doing some
> > > mathematical modeling for an article I am writing..) I have intensity
> > data
> > > for a 30 and 64 watt UV set-up, so I am interpolating a result here.
> > > However, the dosage estimate is really an estimate! Sorry I cannot be
> > more
> > > precise.
> > >
> > > Now its your choice whether to leave on the sterilizer or cycle it. I
> do
> > > not believe the statement that cycling a UV lamp shortens its life
> > > significantly. Maybe it does, but I find it hard to believe. In
fact,
> > the
> > > lamp manufacturer defines its useful life in terms of hours on, not
> number
> > > of cycles. If you leave the thing on all the time, the lamp will last
> > about
> > > 6 months. If you use it only during the day, my expectation is that
it
> > will
> > > last a year. Since your target is algae, maybe its enough to
sterilize
> > when
> > > the algae is multiplying during your tank's lighted period.
> > >
> > > Do some experiments, and see if you perceive a difference in water
> quality
> > > and/or algae proliferation when cycling and not cycling. And then let
> me
> > > know what you conclude! I'd really like to know what your experience
> > turns
> > > out to be...
> > >
> > > -Bruce
> > >
> > > http://www.wideopenwest.com/~brucegeist
> > >
> > > "Christopher" > wrote in message
> > > rthlink.net...
> > > > Thats a very detailed explanation, THANKS!
> > > > have a couple questions though:
> > > > if the primary reason I'm using the steralizer is to kill algae
spores
> > so
> > > my
> > > > tank stays clean is it smart to only have the steralizer running for
X
> > > hours
> > > > a day? Cant the spores be released and land and settle on the glass
> and
> > > > leaves during the off period? My second question is how much life
of
> > the
> > > > bulb is saved when you run it for 8 hours a day? I know that the
> turning
> > > on
> > > > of the bulb takes away from bulb life, but would the fact that its
> only
> > > run
> > > > for 1/3 of the time save bulb life in the long term? I am concerned
> > since
> > > > 36W PC florescents are $50 (not exactly cheap)
> > > >
> > > > "Bruce Geist" > wrote in message
> > > > ...
> > > > >
> > > > > Actually, the 9.2 factor will give you 99.99 % throughput through
> the
> > > > > sterilizer. To get 99.9% throughput, the factor is 6.9.
> > > > > See http://www.wideopenwest.com/~brucegeist/turnover/index.html
> > > > > for details.
> > > > >
> > > > > One strategy is to set the flow rate through the sterilizer so
that
> > one
> > > > pass
> > > > > kills target organisms you wish to kill. If you set the flow rate
> > slow
> > > > > enough that everything you want to kill is killed, then run your
> > > > sterilizer
> > > > > long enough to "turnover" the tank water once or twice a day,
> > > > > and then shut the sterilizer off.
> > > > >
> > > > > Basically, the more slowly you put water through the sterilizer,
the
> > > more
> > > > UV
> > > > > exposure every bit of water passing through the sterilizer
> receives.
> > > > If
> > > > > you have a 36 watt sterilizer with about a 3 inch diameter chamber
> for
> > > the
> > > > > water, and your flow rate is about 100 gallons per hour, then you
> are
> > > > > probably irradiating your water at about a 100 microwatt-seconds
> dose,
> > > > which
> > > > > is
> > > > > enough to kill most bacteria, algae, and many protozoa. (This is
> only
> > a
> > > > > crude estimate; I am working on developing some assessment tools
on
> my
> > > > > website which will provide more specific advice..) If you are
using
> a
> > > > lower
> > > > > wattage sterilizer, or a lower diameter sterilizer, then your flow
> > rate
> > > > will
> > > > > need to be lower still to achieve the same dose.
> > > > >
> > > > > In the article I wrote cited above, I show that when you have run
> > 99.9%
> > > of
> > > > > the water through the sterilizer at least one time, in actuality
> 99.2%
> > > of
> > > > > water has passed through 2 or more times, and 96.8% will have
passed
> > > > through
> > > > > the sterilizer 3 or more times! I recommend 6.9*(tank size in
> > > > > gallons)/(flow rate in gallons) to be your target turnover time.
If
> > > your
> > > > > flow rate is chosen with some care, you need not run your
sterilizer
> > all
> > > > > the time. You will save bulb life by running your sterilizer
> through
> > > only
> > > > > one or two
> > > > > turn-over intervals per day.
> > > > >
> > > > > I hope you enjoy the article on turnover time; this is the first
> time
> > I
> > > > have
> > > > > published the web address. Remember that you can skip to the
> > conclusion
> > > > > and get the formula to use. I am in process of collecting data
for
> a
> > > > suite
> > > > > of articles on the topic UV sterilizers. Be watching this news
> group
> > or
> > > > my
> > > > > web site; I am waiting on data from a manufacturer. -Bruce Geist
> > > > >
> > > > > "Christopher" > wrote in message
> > > > > rthlink.net...
> > > > > > is it wise to run the UV steralizer 24 hours a day? assuming
that
> > you
> > > > only
> > > > > > desire a 99.9% steralization rate you don't have to run the
> > steralizer
> > > > > that
> > > > > > much (depending upon gph through the steralizer and tank size).
> > I've
> > > > > read:
> > > > > >
> > > > > > 9.2 * (tank size / gph through steralizer) = hours a day UV
> > > steralizer
> > > > > must
> > > > > > be on to attain 99.9% steralization rate (assuming uniform
> mixing).
> > > > This
> > > > > > said my calculation is at most 7 hours a day, should I just run
it
> > for
> > > 8
> > > > > > hours a day and save my bulb life and power bill?
> > > > > >
> > > > > > Should I run it 24 hours a day to achieve 99.999% steralization
or
> > for
> > > 8
> > > > > > hours a day?
> > > > > >
> > > > > >
> > > > >
> > > > >
> > > > >
> > > >
> > > >
> > >
> > >
> >
> >
> >
>
>

[liz bolyard-mick]

I may be wrong, but I believe that only incandescent bulb life is shortened
by turning it off and on due to the surge of electricity passing through the
filament. This surge weakens the filament by vaporizing pieces of the
filament. During normal usage, samll pieces of the filament detatch and
float freely in the bulb, but they are drawn back to the filament to settle
on it. It is the vaporization of the small pieces of the filament that
shortens the life of an incandescent bulb. I don't believe the same is true
for any flourescing type lamp, but I don't know as much about those types.

"Bruce Geist" > wrote in message
...
> Basically, you are only culling the population of algae spores and
bacteria
> to a level, presumably, that is more like an open stream or lake. All
tank
> water is never sterile at any one moment in time, since algae and bacteria
> are constantly re-growing.
>
> To control a specific organism or class of organisms, use the lowest
lethal
> dose for that organism or class of organism, meaning you turn your flow
rate
> up so that water passing though is exposed to the right level of
radiation,
> and no more. That way, you are killing algae at the quickest possible
> rate. The flow rate is effectively your control on the dosage you are
> delivering. So, if algae is your target, I'd turn your flow rate to about
> 200 gallons per hour. This will deliver (I am estimating here) about
50,000
> micro watt-seconds / cm^2 of radiation to the water passing through your
> sterilizer.
>
> Here is the shaky part; I am not sure exactly what dose will kill all
algae.
> So be aware, I am making a swag here. I do know that Chlorella Vulgaris,
a
> kind of algae, is killed by 45,000 micro watt-seconds / cm^2 of UV.
> Therefore, I am recommending a flow rate that I believe will cause your
36
> watt sterilizer to deliver the 50 K micro watt-seconds / cm^2 dosage. I
do
> not actually have intensity data for your particular sterilizer, though I
> have requested it from the manufacturer (because I am doing some
> mathematical modeling for an article I am writing..) I have intensity
data
> for a 30 and 64 watt UV set-up, so I am interpolating a result here.
> However, the dosage estimate is really an estimate! Sorry I cannot be
more
> precise.
>
> Now its your choice whether to leave on the sterilizer or cycle it. I do
> not believe the statement that cycling a UV lamp shortens its life
> significantly. Maybe it does, but I find it hard to believe. In fact,
the
> lamp manufacturer defines its useful life in terms of hours on, not number
> of cycles. If you leave the thing on all the time, the lamp will last
about
> 6 months. If you use it only during the day, my expectation is that it
will
> last a year. Since your target is algae, maybe its enough to sterilize
when
> the algae is multiplying during your tank's lighted period.
>
> Do some experiments, and see if you perceive a difference in water quality
> and/or algae proliferation when cycling and not cycling. And then let me
> know what you conclude! I'd really like to know what your experience
turns
> out to be...
>
> -Bruce
>
> http://www.wideopenwest.com/~brucegeist
>
> "Christopher" > wrote in message
> rthlink.net...
> > Thats a very detailed explanation, THANKS!
> > have a couple questions though:
> > if the primary reason I'm using the steralizer is to kill algae spores
so
> my
> > tank stays clean is it smart to only have the steralizer running for X
> hours
> > a day? Cant the spores be released and land and settle on the glass and
> > leaves during the off period? My second question is how much life of
the
> > bulb is saved when you run it for 8 hours a day? I know that the turning
> on
> > of the bulb takes away from bulb life, but would the fact that its only
> run
> > for 1/3 of the time save bulb life in the long term? I am concerned
since
> > 36W PC florescents are $50 (not exactly cheap)
> >
> > "Bruce Geist" > wrote in message
> > ...
> > >
> > > Actually, the 9.2 factor will give you 99.99 % throughput through the
> > > sterilizer. To get 99.9% throughput, the factor is 6.9.
> > > See http://www.wideopenwest.com/~brucegeist/turnover/index.html
> > > for details.
> > >
> > > One strategy is to set the flow rate through the sterilizer so that
one
> > pass
> > > kills target organisms you wish to kill. If you set the flow rate
slow
> > > enough that everything you want to kill is killed, then run your
> > sterilizer
> > > long enough to "turnover" the tank water once or twice a day,
> > > and then shut the sterilizer off.
> > >
> > > Basically, the more slowly you put water through the sterilizer, the
> more
> > UV
> > > exposure every bit of water passing through the sterilizer receives.
> > If
> > > you have a 36 watt sterilizer with about a 3 inch diameter chamber for
> the
> > > water, and your flow rate is about 100 gallons per hour, then you are
> > > probably irradiating your water at about a 100 microwatt-seconds dose,
> > which
> > > is
> > > enough to kill most bacteria, algae, and many protozoa. (This is only
a
> > > crude estimate; I am working on developing some assessment tools on my
> > > website which will provide more specific advice..) If you are using a
> > lower
> > > wattage sterilizer, or a lower diameter sterilizer, then your flow
rate
> > will
> > > need to be lower still to achieve the same dose.
> > >
> > > In the article I wrote cited above, I show that when you have run
99.9%
> of
> > > the water through the sterilizer at least one time, in actuality 99.2%
> of
> > > water has passed through 2 or more times, and 96.8% will have passed
> > through
> > > the sterilizer 3 or more times! I recommend 6.9*(tank size in
> > > gallons)/(flow rate in gallons) to be your target turnover time. If
> your
> > > flow rate is chosen with some care, you need not run your sterilizer
all
> > > the time. You will save bulb life by running your sterilizer through
> only
> > > one or two
> > > turn-over intervals per day.
> > >
> > > I hope you enjoy the article on turnover time; this is the first time
I
> > have
> > > published the web address. Remember that you can skip to the
conclusion
> > > and get the formula to use. I am in process of collecting data for a
> > suite
> > > of articles on the topic UV sterilizers. Be watching this news group
or
> > my
> > > web site; I am waiting on data from a manufacturer. -Bruce Geist
> > >
> > > "Christopher" > wrote in message
> > > rthlink.net...
> > > > is it wise to run the UV steralizer 24 hours a day? assuming that
you
> > only
> > > > desire a 99.9% steralization rate you don't have to run the
steralizer
> > > that
> > > > much (depending upon gph through the steralizer and tank size).
I've
> > > read:
> > > >
> > > > 9.2 * (tank size / gph through steralizer) = hours a day UV
> steralizer
> > > must
> > > > be on to attain 99.9% steralization rate (assuming uniform mixing).
> > This
> > > > said my calculation is at most 7 hours a day, should I just run it
for
> 8
> > > > hours a day and save my bulb life and power bill?
> > > >
> > > > Should I run it 24 hours a day to achieve 99.999% steralization or
for
> 8
> > > > hours a day?
> > > >
> > > >
> > >
> > >
> > >
> >
> >
>
>

[NetMax]

I agree with liz regarding incandescent bulb life being shortened by
power cycling, though I always attributed it to the temperature cycling
(effectively causing the metal filament to fatigue). Cycling fluorescent
bulbs is also supposed to reduce their life expectancy, but I don't know
the mechanism. The ballasts will also be a consideration. I'd contact
the manufacturer to see what they recommend for maximum life. One of the
fluorescent manufacturers (Phillips, GE etc) might have data on their
websites as well.

note to Donald, ..turnover/..html... book-marked :o)
NetMax

"liz bolyard-mick" > wrote in
message ...
> I may be wrong, but I believe that only incandescent bulb life is
shortened
> by turning it off and on due to the surge of electricity passing
through the
> filament. This surge weakens the filament by vaporizing pieces of the
> filament. During normal usage, samll pieces of the filament detatch and
> float freely in the bulb, but they are drawn back to the filament to
settle
> on it. It is the vaporization of the small pieces of the filament that
> shortens the life of an incandescent bulb. I don't believe the same is
true
> for any flourescing type lamp, but I don't know as much about those
types.
>
> "Bruce Geist" > wrote in message
> ...
> > Basically, you are only culling the population of algae spores and
> bacteria
> > to a level, presumably, that is more like an open stream or lake.
All
> tank
> > water is never sterile at any one moment in time, since algae and
bacteria
> > are constantly re-growing.
> >
> > To control a specific organism or class of organisms, use the lowest
> lethal
> > dose for that organism or class of organism, meaning you turn your
flow
> rate
> > up so that water passing though is exposed to the right level of
> radiation,
> > and no more. That way, you are killing algae at the quickest
possible
> > rate. The flow rate is effectively your control on the dosage you
are
> > delivering. So, if algae is your target, I'd turn your flow rate to
about
> > 200 gallons per hour. This will deliver (I am estimating here) about
> 50,000
> > micro watt-seconds / cm^2 of radiation to the water passing through
your
> > sterilizer.
> >
> > Here is the shaky part; I am not sure exactly what dose will kill all
> algae.
> > So be aware, I am making a swag here. I do know that Chlorella
Vulgaris,
> a
> > kind of algae, is killed by 45,000 micro watt-seconds / cm^2 of UV.
> > Therefore, I am recommending a flow rate that I believe will cause
your
> 36
> > watt sterilizer to deliver the 50 K micro watt-seconds / cm^2 dosage.
I
> do
> > not actually have intensity data for your particular sterilizer,
though I
> > have requested it from the manufacturer (because I am doing some
> > mathematical modeling for an article I am writing..) I have
intensity
> data
> > for a 30 and 64 watt UV set-up, so I am interpolating a result here.
> > However, the dosage estimate is really an estimate! Sorry I cannot
be
> more
> > precise.
> >
> > Now its your choice whether to leave on the sterilizer or cycle it.
I do
> > not believe the statement that cycling a UV lamp shortens its life
> > significantly. Maybe it does, but I find it hard to believe. In
fact,
> the
> > lamp manufacturer defines its useful life in terms of hours on, not
number
> > of cycles. If you leave the thing on all the time, the lamp will
last
> about
> > 6 months. If you use it only during the day, my expectation is that
it
> will
> > last a year. Since your target is algae, maybe its enough to
sterilize
> when
> > the algae is multiplying during your tank's lighted period.
> >
> > Do some experiments, and see if you perceive a difference in water
quality
> > and/or algae proliferation when cycling and not cycling. And then
let me
> > know what you conclude! I'd really like to know what your experience
> turns
> > out to be...
> >
> > -Bruce
> >
> > http://www.wideopenwest.com/~brucegeist
> >
> > "Christopher" > wrote in message
> > rthlink.net...
> > > Thats a very detailed explanation, THANKS!
> > > have a couple questions though:
> > > if the primary reason I'm using the steralizer is to kill algae
spores
> so
> > my
> > > tank stays clean is it smart to only have the steralizer running
for X
> > hours
> > > a day? Cant the spores be released and land and settle on the
glass and
> > > leaves during the off period? My second question is how much life
of
> the
> > > bulb is saved when you run it for 8 hours a day? I know that the
turning
> > on
> > > of the bulb takes away from bulb life, but would the fact that its
only
> > run
> > > for 1/3 of the time save bulb life in the long term? I am
concerned
> since
> > > 36W PC florescents are $50 (not exactly cheap)
> > >
> > > "Bruce Geist" > wrote in message
> > > ...
> > > >
> > > > Actually, the 9.2 factor will give you 99.99 % throughput through
the
> > > > sterilizer. To get 99.9% throughput, the factor is 6.9.
> > > > See http://www.wideopenwest.com/~brucegeist/turnover/index.html
> > > > for details.
> > > >
> > > > One strategy is to set the flow rate through the sterilizer so
that
> one
> > > pass
> > > > kills target organisms you wish to kill. If you set the flow
rate
> slow
> > > > enough that everything you want to kill is killed, then run your
> > > sterilizer
> > > > long enough to "turnover" the tank water once or twice a day,
> > > > and then shut the sterilizer off.
> > > >
> > > > Basically, the more slowly you put water through the sterilizer,
the
> > more
> > > UV
> > > > exposure every bit of water passing through the sterilizer
receives.
> > > If
> > > > you have a 36 watt sterilizer with about a 3 inch diameter
chamber for
> > the
> > > > water, and your flow rate is about 100 gallons per hour, then you
are
> > > > probably irradiating your water at about a 100 microwatt-seconds
dose,
> > > which
> > > > is
> > > > enough to kill most bacteria, algae, and many protozoa. (This is
only
> a
> > > > crude estimate; I am working on developing some assessment tools
on my
> > > > website which will provide more specific advice..) If you are
using a
> > > lower
> > > > wattage sterilizer, or a lower diameter sterilizer, then your
flow
> rate
> > > will
> > > > need to be lower still to achieve the same dose.
> > > >
> > > > In the article I wrote cited above, I show that when you have run
> 99.9%
> > of
> > > > the water through the sterilizer at least one time, in actuality
99.2%
> > of
> > > > water has passed through 2 or more times, and 96.8% will have
passed
> > > through
> > > > the sterilizer 3 or more times! I recommend 6.9*(tank size in
> > > > gallons)/(flow rate in gallons) to be your target turnover time.
If
> > your
> > > > flow rate is chosen with some care, you need not run your
sterilizer
> all
> > > > the time. You will save bulb life by running your sterilizer
through
> > only
> > > > one or two
> > > > turn-over intervals per day.
> > > >
> > > > I hope you enjoy the article on turnover time; this is the first
time
> I
> > > have
> > > > published the web address. Remember that you can skip to the
> conclusion
> > > > and get the formula to use. I am in process of collecting data
for a
> > > suite
> > > > of articles on the topic UV sterilizers. Be watching this news
group
> or
> > > my
> > > > web site; I am waiting on data from a manufacturer. -Bruce Geist
> > > >
> > > > "Christopher" > wrote in message
> > > > rthlink.net...
> > > > > is it wise to run the UV steralizer 24 hours a day? assuming
that
> you
> > > only
> > > > > desire a 99.9% steralization rate you don't have to run the
> steralizer
> > > > that
> > > > > much (depending upon gph through the steralizer and tank size).
> I've
> > > > read:
> > > > >
> > > > > 9.2 * (tank size / gph through steralizer) = hours a day UV
> > steralizer
> > > > must
> > > > > be on to attain 99.9% steralization rate (assuming uniform
mixing).
> > > This
> > > > > said my calculation is at most 7 hours a day, should I just run
it
> for
> > 8
> > > > > hours a day and save my bulb life and power bill?
> > > > >
> > > > > Should I run it 24 hours a day to achieve 99.999% steralization
or
> for
> > 8
> > > > > hours a day?
> > > > >
> > > > >
> > > >
> > > >
> > > >
> > >
> > >
> >
> >
>
>

[LeighMo]

> I know for most people it isn't a big deal but I don't like algae
>in my tank and for me...

It's not just you. Most people hate algae in the tank.

>That way I can run the lights more than 8 hours a day
>and I don't have to spend an hour scraping the sides of the tank every other
>week.

Most people don't have UV sterilizers and don't have to spend an hour scraping
the tank, either. If your tank is in balance, your algae problems should be
minimal.

And you should have your lights on more than eight hours a day. Aquarium
plants generally need a 12 hour day. You should not go below 10 hours. Too
short a photo period can actually help algae, since the plants won't be growing
as well as they should.



Leigh

http://www.fortunecity.com/lavender/halloween/881/

[Christopher]

well I'm up to 12 hours of full light and 30 minutes of sunrise and 30
minutes of sunset

full light is 120W (80W power-glo 40W actinic 03)
sunrise/sunset is 40W actinic 03
all over a 125g

"LeighMo" > wrote in message
...
> > I know for most people it isn't a big deal but I don't like algae
> >in my tank and for me...
>
> It's not just you. Most people hate algae in the tank.
>
> >That way I can run the lights more than 8 hours a day
> >and I don't have to spend an hour scraping the sides of the tank every
other
> >week.
>
> Most people don't have UV sterilizers and don't have to spend an hour
scraping
> the tank, either. If your tank is in balance, your algae problems should
be
> minimal.
>
> And you should have your lights on more than eight hours a day. Aquarium
> plants generally need a 12 hour day. You should not go below 10 hours.
Too
> short a photo period can actually help algae, since the plants won't be
growing
> as well as they should.
>
>
>
> Leigh
>
> http://www.fortunecity.com/lavender/halloween/881/
>

[tcbiii@NOSPAMearthlink.net]

"Christopher" >

UV's have a couple of planted tank uses.
One is for green water
The other is for the 24 hour period after a water change.
So you will only need to use it once a week after the 50% water
change.
They do no good after this period.

I don't use them on my tanks personally. Don't need too.

Try a credit card for getting algae off the glass.
I think you'll find this is the best use for a credit card rather than
it's intended purpose.

If you address the CO2/nutrients, cleaning the glass is seldom an
issue.

Regards,
Tom Barr

[LeighMo]

>The other is for the 24 hour period after a water change.

Why for a 24 hour period after a water change? (Just curious -- I've never
heard that one before.)

I originally got my UV sterilizer to prevent ich. I just couldn't face
prophylactic treatment with chemicals for a 75 gallon tank, over the long weeks
of stocking using Chuck's "no-cycle" setup.

I've left it on since, mainly to knock bacteria levels down closer to the
natural levels you find in lakes and streams, but I'm thinking of turning it
off. It's one more powerhead to clean, and I'm lazy!


Leigh

http://www.fortunecity.com/lavender/halloween/881/