danath256

I have had no problems with my tank before. Everything was just fine.

I went away for a week and left my mom to just feed my fish, and now I have green water, The only thing I knew she did was left the window open so sunlight was probably shining on the tank for couple hours every day (I read somewhere thats bad)

I have my lights on a timer and did a 75% water change but it still looked cloudy and is now green again not as bad though

My levels are
PH 6.6
Nitrate less than 5.0
Nitrite 0
Ammonia 0

smillermom

I had the same thing happen to me when my daughter cared for my tank.* What a mess!* I ended up doing this which worked well. Do a water change, turn the lights off in the tank and totally cover the tank so no light at all gets in.* Leave it like this for a full 4 days. Then, uncover, do a 50% change of water and it should take care of the problem. Your fish can go without food for the 4 days.* Your mom may have overfed them also.

Jmarcus

I was having trouble with green water and cut back on fish food, added another filter, and some more plants, awoke two days later tank kristal clear.I suspect that over feeding was main cause.

Isabella

Yes, only when you feed the fish, you have to be careful, because a sudden exposure to light (after a long period of darkness) can send fish into a sort of respiratory shock that may kill them - not kidding. That's what often happens to fish that travel for long periods in total darkness.