Green Water

[Tammy1964]

I have three established freshwater tanks. In the last six months, every time I change the water it turns very green within 3-7 days. It quickly gets to the point where I can't see the fish. My filters seem to be working fine. I just can not figure out why this is happening. Anyone? Thank you

 

[bud29]

What light do you have, and typically how long is it on each day? Are you dosing fertilizer? Some people use UV sterilizers to treat green water, however, to really nail down what is causing the issues we'll probably need more specifics.

 

[Tammy1964]

I have the same light that came with the aquarium when I purchased it. After this problem started about six months ago I tried keeping the light off after cleaning the tank and changing the water. No improvement. We are on a community well system so I thought maybe it's the water itself but it hasn't affected the third tank. My test strips read the same for both the normal and the green water. And I have no live plants and don't add fertilizer. I'm completely stumped.

 

[Scottyhorse]

Do you have green gravel? Any decor with green on it?

 

[Tammy1964]

No green gravel. I've had and have used this tank for 8yrs. No trouble until about 6 months ago. The "green" doesn't grow on or seem to stick to the tank, plants or rocks either. I've added nothing new to the tank in terms of decorations. I'm baffled.

 

[Scottyhorse]

Hmmm.... That is odd. My guess is something is growing in the water. You could get a UV sterilizer for the tank.

 

[Rivercats]

An algae bloom typically is from too much light with excess nutrients. The reason it keeps coming back, even after black outs (which only work sometimes) is because not all the free floating algae gets removed from the tank and it only takes a few algae cells to rapidly reproduce and rebloom. In this type of case a UV sterilizer is absolutely the best way to kill off the algae in the water. This little unit is pretty reasonably priced and should clear the tank in 24 hours or longer if it's a really heavy bloom. Green Killing Machine Internal UV Sterilizer with Power Head at PETCO Many people on this forum have used it with good results. Also remember if you use nets, etc., in a tank with an algae bloom you can transfer the free floating algae into other tanks and can start blooms in them.

I don't know what kind of lights you have but you should only run your lights 6-8 hours daily and be sure to do WC's weekly to keep nutrient levels low with nitrates no higher than 20ppm.

 

[Tammy1964]

I'll jump on that. Thanks so very much!!!

 

[Mudfrog]

I fought green water for a very long time. I have a UV sterilizer and I even purchased a diatom filter but nothing helped. Turns out it was my duckweed giving the water a green tint. Removed the duckweed and the green water was gone. Probably not your issue but that was mine.

 

[BBradbury]

I have three established freshwater tanks. In the last six months, every time I change the water it turns very green within 3-7 days. It quickly gets to the point where I can't see the fish. My filters seem to be working fine. I just can not figure out why this is happening. Anyone? Thank you

Hello Tam...

After just six months, the fish, plants and water are still working to level the water chemistry, so there will be algae problems. I understand a floating plant called Anacharis contains an antibiotic that's toxic to some forms of algae. I've used it in my planted tanks for years, because I liked the look of it and I don't notice much algae in my tanks. Granted they've been running longer than yours.

Check the ingredients of food you feed. Phosphates can cause water chemistry problems if you feed too much.

Keep up the water changes. They're the most important to guarantee a stable water chemistry.

B