So I have a very, very bad case of green water in my planted 55 gal
. I have a borrowed 9W UV
sterilizer that I just got a bulb for last night. I don't have a canister filter so I jury-rigged a small powerhead (250 liters/hour or about 1 tank volume per hour) to the UV
. As of this AM it had been on for ~12 hours with no visible difference in the tank. How long should it take before I see a change? Also, there is no way to tell if the darn thing is even on; we have a big UV
here at work and you can see the purple light out the end but I can't with the little one....not sure if I'm supposed to or not, don't really want to take it apart and look with it on (ouch). Advice??