I have set up a 50 gal planted aquarium and about 3 weeks in the tank went cloudy almost over night. It remains cloudy almost 4 weeks after.

During this 4 weeks, I have tested water weekly and there is nothing wrong. I have done weekly 30-40% water changes and the cloud returns, again almost over night. The fish in the tank are still living and they do not seem to be bothered at all. The plants, when I can see them, are growing like wild. What is wrong?

There are times when i can only see in the tank about 2in. at best...this is a serious cloud.

Recently I have noticed if I leave my tank light off the cloud seems to lessen quite a bit. But I need the tank light for the plants.

Any suggestions?

I really want to get this problem worked out so I can enjoy this tank, the plants and the fish. Thanks for all your help

Sounds like a bacterial bloom or most likely an algae bloom, especially since you mention your lighting... how long are you leaving the lighting on? Also, what color is the cloud? (it may seem white, but sometimes a green algae bloom will only show greenish when you do a water change and you can pour the water over a white background). Water changes don't help much for an algae bloom, well not for one that i had atleast. If it is determined its an algae bloom, Tetra Algae Control works wonders in about 3 hours your water will be crystal clear... but make sure its an algae bloom since this med does affect your nitrites.

Also, give us any usual info on your maintenance, how often u feed, etc. Any extra info will help us figure out the issue.

so by pulling down the tank, what do you mean exactly? that you took out all the water and ornaments? If so, this cloud is a bacterial bloom and will disappear when your tank recycles.... if you didn't break your cycle its most likely an algae bloom and will look quite clear sometimes. Especially if you had algae outbreak right before the cloud. what color was this algae on the glass, what did it look like, and how easy was it to scrape off?

I did completely break down the tank 7 weeks ago....everything new. New filter, new lighting, new substraight, and new live plants. I had gravel and plastic plants before....this was a complete change. I wanted a live plant tank. I also have co2 and a regulator in the tank.

As far as the algee on the back, it was green and slightly stringy, but mostly it looked like a thin carpet. it was very easy to get off. I simply used a coarse scrubber. i did not have to use a razor blade.

It was about three days after i cleaned the algee from the back that the tank went cloudy. Since then, I have been doing weekly water changes of 30-40%. This helps for awhile but has never made it perfect.

I am possitive the lighting has something to do with it; however, even when I leave it off for 24 hours it does not clear out completely. If I run the light for 10-12 hours, the cloud is horrible.

I am hoping this is a bacteria bloom because everything I have read tells me it will eventually clear up. I have also been told that a UV sterlizer will help. I kind of want it to clear up before I spend anymore money.

oh, and when u clean, do u really stir things up, this will sometimes cause a bacterial bloom?