laga77
New member
Picked up a flame angel and golden headed sleeper three days ago. They are in a 30 gal QT with a sand bottom and some cycled rock. There is a HOB filter with carbon and floss and a small HOB protein skimmer. After the first night I noticed a few white spots on the flame. I hooked up a 55watt UV sterilizer from Amazon and a diatom filter. After about two hours I checked on the fish and they were in distress. Heavy breathing and laying on the bottom. My only guess at the time was the impeller of the diatom filter had somehow effected the gas levels of the water since I had a ball valve at the discharge to slow water flow. After shutting off the diatom and sterilizer I pulled water from the tank and poured between two buckets and back into the tank about twenty times. Luckily, I had guessed right as the fish recovered. Today I tried just the sterilizer with a submersible Rio pump rated at 1500 LPH, no ball valve. After an hour they showed distress and I immediately stopped the UV and the fish are fine. So, it was not the diatom, it was the UV creating the problem. The temperature of the water did not change with the UV. Now, I have an identical UV running for the past 6 weeks on my 120 gal reef with no problems and I run the diatom occasionally on the 120 and a 50 gal reef as a clarifier and water polisher as needed. Like after a major cleaning. I am at a complete lost for an explanation. I cannot find any info about UV effecting oxygen levels, only about UV causing formation of ozone. Any ideas?