What do you think of UV sanitizers?

[alanmin4304]

I don't know much about the commercial ones available now because the last one I used was one I built myself for treating seawater for a cold water marine setup. The water is usually in contact with the bulb so the bulb and the water need to be kept clean or there will be not enough penetration of UV, and the water needs to be passing through it at the rate specified or there will be not enough contact time. I would suspect you are overfeeding and providing food for the algae. The only tanks I have that "problem" in are my turtle tanks because they are such heavy and dirty feeders. I use the green water to culture daphnia so it is not a problem. It would take a very fine filter to remove it (like a diatom-- down below one micron) and it would clog quickly.

[JoandWilly]

Ryan, your green water problem sounds like something thats really common on the north shore, no one has yet pin pointed its cause, have tested tanks with green water and nitrates and phosphates can be low, nitrite and ammonia is 0, pH is fine and lights are fine and running the right amount of time, and no direct sunlight on the tank, have even seen 2 tanks side by side, both using the same light tube and one tank gets it and the other doesn't and have tested everything and no found a cause. Not sure if its a algae or bacteria, but in my experience no amount of water changes fix's the problem, it just keeps coming back. Best way to get rid of it is use a UV sterilizer, but if not one way is to use a water clarifer (either clarity or magic clear work best) and use filter wool in your filter and just filter the green water out, if your using a desent filter this can be done quickly, but should be carried on after your tank is clear just to make sure you get all of it.