# Clear tank + UV sterilizer = cloudy water???



## FD3S (Mar 12, 2006)

I have a 55g running compressed co2, Greg Watson ferts, excel and 220w vho lighting. I've never had a water clarity problem for as long as the tank has been running. Whenever a fish would die without being noticed for a while, it would be covered with fuzzy white crap. I took that to be a bacteria problem. I bought a coralife 9w UV sterilizer, got it running on the tank hooked up to a powerhead, and a few hours later, the water is cloudy. It's a whitish cloudy like when my cichlids stir up sand in the 90g, but there is no sand in this tank. 

What would be causing this? 

Should I leave the sterilizer running?


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## Overfloater (Jan 12, 2004)

A UV sterilizer will never cuase cloudy water. In fact you should have water so clear, it's like it's not even there. The white stuff growing on dead fish is most likely a fungus. That's a normal part of the decomposition process and nothing to worry about. 

How long has the tank been running?


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## Rod Hay (Feb 11, 2006)

On one of my tanks once when I hooked up and ran a UV it went cloudy the second day, then the third day it was crystal clear. I'm thinking that some organisms in the water which were being zapped caused the cloudiness, then the filter took them out.


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## dhavoc (May 4, 2006)

happens on my tank also. i installed a uv light to combat green water and it took care of that great, but ever since then the water gets this milky tinge. its not gw, i checked in a white container, so i assumed it was a bacterial bloom of some sort, so i leave the uv on 24/7. do major water changes and it just gets milky again in a couple of days. fish and plants dont seem to care but it is annoying. might try a diatom filter but i think thats only a temp fix as well.


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## unirdna (Jan 22, 2004)

Are you dosing an iron supplement?

http://www.plantedtank.net/forums/g...iron-uv-sterilizer-experiment-conclusion.html


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## FD3S (Mar 12, 2006)

unirdna said:


> Are you dosing an iron supplement?
> 
> http://www.plantedtank.net/forums/g...iron-uv-sterilizer-experiment-conclusion.html


Yes I am. I believe there is some iron in the CSM+B, and I dose flourish liquid iron supplement. If the sterilizer is going to precipitate the iron out of the water, how am I supposed to get iron to the plants?


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## spypet (Sep 15, 2006)

FD3S said:


> I bought a coralife 9w UV sterilizer, got it running on the tank hooked up to a powerhead, and a few hours later, the water is cloudy. It's a whitish cloudy like


I have the same problem with my 9w UV that I run the first 24 hours after a water change. I simply hope the UV is helping, and ignore the unexplained white tint in my water. about 6 hours after I turn the UV off my water is clear. algae turns white when bleach kills it off, so perhaps micro organisms and micro algae killed by the UV are likewise turning white. who knows...


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## Blacksunshine (Oct 11, 2006)

yep. the cloudyness is the death of all the little buggers in the water. it should clear in a day or so with decent filtration. Or possibly it may be a reaction with your ferts. in a planted tank you should only use the UV when it's needed. not 24/7. Greenwater breaks out. Use it, stop ferts. let water clear, Resume ferts.


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