Correct, UV sterilizers are designed to have a short path of a cm or less.
Spectrophotomers are designed to measure particulates that cannot be seen with the
naked eye. What appears to be "clear water" can actually be full of particulates.
OK. I have a 25 watt UV. p. 334-335 aquatic ecosystem cat.
One of their 25 watt models is rated for 15,000 mws at 12.6 gallons per minute.
Killing algae requires 22,000 mws so gotta slow the flow to 8.6 gallons per minute.
My maxi 1000 runs at 230 gph or 3.8 gallons per minute.
Aquatic Eco recommends the entire volume of the pond goes thru the UV 4 times per 24
hours.
My pond is 1800 gallons, at 230 gallons per hour it takes 7.8 hours for 1X, so only
get 3X+ per 24 hours.
-----------------------------
my UV had been used at least 1 year before somebody gave it to me. I have now been
using it for 4 years without changing the bulb. After 6 months the efficiency can
fall 40%, so each 6 months sees a 40% drop off... and after 5 years that means 10
"half lives" (60% after 6 months, 36% 1 year, 12.9%- 2 years, 4.66%-3 years, 1.67%-4
years, etc.)
So even being generous that the efficiency could still be 10%, that means to get
22,000 mws it has to be 1/10 the flow rate or 0.86 gallons per minute, but mine runs
at 3.8 gallons per minute or 4.4 times too fast to attain 22,000 mws. so now I am
only getting 5,000 mws at 3.8 gpm. This is way below killing for algae. We wont
count the particulates in my pond, nor the yellow coloring as my water is not gin
clear. Both these affect kill and AES recommends getting UV lights 40% over what is
minimum.
So all of this is very interesting cause this spring I had pea soup, cranked up the
UV and in 4 days the pea soup was gone.
--------------------------
what I did observe is that algae that had been flowing wild and free thru my filter
for some reason ended up sliming my filter after I cranked the UV up. Now UV creates
cross links in the DNA of cells. So if the only change to the algae was inactivating
the DNA it should flow thru the filter just the same as before gradually
disintegrating, not load my filters up with green gunk.
So what I got here is a bona fide miracle, cause there is no way that old UV is
"killing" my algae... not according to the "specs". And it is one reason I tell
people to save their money, dont change their UV bulbs until pea soup returns.
Ingrid
Andrew Burgess wrote:
UV purifiers look like they have an inch
or two of water for the UV to pass through. Can we agree its probably not
significant in the first two inches?
few people have gin clear
water which has the highest transmission to UV.
Of course the clearer the better the transmission.
A spectrophotometer is probably one
of the only ways to show how many "particulates" and colored soluble molecules there
are in pond water. The other is a disk that is lowered into the water and there are
numbers and it shows how turbid the water is.. I think aquatic ecosystems has some of
these. this is a really crude measure of course, a spectrophotometer is accurate.
So?
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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http://puregold.aquaria.net/
www.drsolo.com
Solve the problem, dont waste energy finding who's to blame
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