I am sure this has been posted many times, so please excuse me.

A while back I saw a post about using UV filters to remove algae. This
puzzles me. Algae thrives on UV from sunlight, so how do these filters
differ? How efficient are they? I have a 120 gal pond and am considering
a filter which combines a pressure filter and UV clarifier. Nurserypro
Ultraklean 500 gal.

My present filter is a pair of foam rubber filters in plastic boxes 6x3x3 in
and I have to clean daily.

Martin Oakes

I don't use UV but from other rec.ponders who
use it and really like it ---- it works by roughing
up the cell wall of the single cell algae as it
passes under the light. The mortally injured algae
then dies.
You'll still have to clean your filter pads as the
dead algae piles up, that which does not fall
to the bottom of the pond.
Bigger filters help the daily cleaning problem.

I used a 150 gallon stock tank as a filter for a
3,000 gallon pond. The media was 50 yards of
black vinyl screening which worked as a mechanical
and bio filter. Cleaned it once a year and there were
no aanaerobic spots in it.

kathy :-)
www.blogfromthebog.com

"Courageous" wrote in message
...

A while back I saw a post about using UV filters to remove algae. This
puzzles me. Algae thrives on UV from sunlight, so how do these filters
differ? How efficient are they? I have a 120 gal pond and am
considering
a filter which combines a pressure filter and UV clarifier. Nurserypro
Ultraklean 500 gal.

They use intense high ultraviolet radiation, at a band that is generally
inimical to life. The one's labelled "sterlizers" are very efficient, and
will kill your algae dead, dead, dead. There is an issue of what wattage
to use. For your pond (err, bucket?), almost any size will do.

Do keep in mind that the only thing they do is kill algae and other
microorganisms (e.g., bacteria). If you have any other problems with
your water, the UV sterilizer won't help.

These don't help with string algae, just the floating green stuff.

You don't need a commercial filter. Just pump your water under some
fine pea gravel and stones like this:

http://www.pondsolutions.com/bog_filter.htm

Interesting setup.

Quercus Robur wrote:

I am sure this has been posted many times, so please excuse me.

A while back I saw a post about using UV filters to remove algae. This
puzzles me. Algae thrives on UV from sunlight,

Algae thrives on light, period. I've never seen anything to indicate that
it's particularly UV, but...

so how do these filters differ?

They're a whole lot more powerful. Sunlight generates something on the
order of 100 Watts/meter squared - spread over all wavelengths. A UV lamp
will generate 10s of Watts over a small fraction of a square meter - but
almost entirely in the UV spectrum.

How efficient are they? I have a 120 gal pond and am
considering a filter which combines a pressure filter and UV clarifier.
Nurserypro Ultraklean 500 gal.

they're very efficient, but imo not a good idea. When you have an algae
problem, it means you have too much nitrate, phosphate or light. Sometimes
it means you have nitrate that can't be used by vascular plants because
they don't have enough of something else (frequently potassium). Killing
the algae with a UV does nothing to resolve that problem - it just makes
the water clear.

My present filter is a pair of foam rubber filters in plastic boxes 6x3x3
in and I have to clean daily.

You won't have any less need to clean a filter that has UV, so if it's not
bigger than your present filter, you'll still need to clean it often.
--
derek

Derek Broughton wrote:
Quercus Robur wrote:

I am sure this has been posted many times, so please excuse me.

A while back I saw a post about using UV filters to remove algae. This
puzzles me. Algae thrives on UV from sunlight,


That my Derek, he is so dead brain bright!

-------------------------------------

CR...

I took a big dump today.

On Wed, 01 Jun 2005 09:53:30 -0300, Derek Broughton
wrote:

UVs
they're very efficient, but imo not a good idea. When you have an algae
problem, it means you have too much nitrate, phosphate or light. Sometimes
it means you have nitrate that can't be used by vascular plants because
they don't have enough of something else (frequently potassium).

Or the pH is too high or low that the plants can't take up the
nitrate. ~ jan

~Power to the Porg, Flow On!~

A while back I saw a post about using UV filters to remove algae. This
puzzles me. Algae thrives on UV from sunlight, so how do these filters
differ? How efficient are they? I have a 120 gal pond and am considering
a filter which combines a pressure filter and UV clarifier. Nurserypro
Ultraklean 500 gal.

They use intense high ultraviolet radiation, at a band that is generally
inimical to life. The one's labelled "sterlizers" are very efficient, and
will kill your algae dead, dead, dead. There is an issue of what wattage
to use. For your pond (err, bucket?), almost any size will do.

Do keep in mind that the only thing they do is kill algae and other
microorganisms (e.g., bacteria). If you have any other problems with
your water, the UV sterilizer won't help.

These don't help with string algae, just the floating green stuff.

You don't need a commercial filter. Just pump your water under some
fine pea gravel and stones like this:

http://www.pondsolutions.com/bog_filter.htm

Instead of using their setup, go to home depot and buy some irrigation
PVC, drill it full of small holes, connect it with elbows, and so forth.

It doesn't have to be very deep. Run your pump 24/7. If you have a problem
with the cost, use a low wattage pump. It's more important to constantly
run the pump than to have very high flow.

The filter should be in a water tight container, and the water should flow back
into your pond somehow. If you get creative, you can connect up some bamboo,
and make it look like a japanese faucet:

http://www.cherryblossomgardens.com/abamboo.asp

C//

Quercus Robur wrote:

I am sure this has been posted many times, so please excuse me.

A while back I saw a post about using UV filters to remove algae. This
puzzles me. Algae thrives on UV from sunlight,

Sorry I missed the original post.

Using UV to kill algae may sound like BS, but read on.
Ultraviolet light kills many things in the water and is effective on
algae as well. Some commercial systems (Pet shops and commercial
fish keepers.) use large amounts of UV and kill lots of junk. See
chart at the end of the article:

http://www.aquaticeco.com/index.cfm/...Detail/ttid/80

Regards,

Hal

Thank you for the comments.
Martin

"Hal" wrote in message
...

Quercus Robur wrote:

I am sure this has been posted many times, so please excuse me.

A while back I saw a post about using UV filters to remove algae. This
puzzles me. Algae thrives on UV from sunlight,

Sorry I missed the original post.

Using UV to kill algae may sound like BS, but read on.
Ultraviolet light kills many things in the water and is effective on
algae as well. Some commercial systems (Pet shops and commercial
fish keepers.) use large amounts of UV and kill lots of junk. See
chart at the end of the article:

http://www.aquaticeco.com/index.cfm/...Detail/ttid/80

Regards,

Hal