I just set up a 25 gallon tank about 1 month ago and everything was doing
well. I bought some fast growing plants (Amazon sword, water sprite,
cabomba, micro sword etc. I added a DIY CO2 and the plants were growing
like mad and bubbling, so I decided to add Flourish fertilizer. About a
week after that the green water started. I stopped fertilizing, removed the
CO2, made a 50% water change and kept the tank in the dark for approx. 3
days. That definetly helped, except the plants suffered some, but the
water is still a light green and still cloudy. I started with the lights
back on only 4 hours a day and then 6 hours, and the green is getting worse
again, so I have gone back to 4.
I am going to do another 50% water change.
My question is, should I start the CO2 again? Will this make a difference
or will it make the situation even worse?
All of the water parameters are fine, with no excessive iron or phosphate
levels, ph around 6.5, nitrate, nitrite and ammonia are low to none.
I have a fluval 104 filter and added a couple of bristle nose plecos about 2
weeks ago, before the green water started, just to clean the algae of the
plants leaves etc. and they have done a great job. Too bad they can't eat
it out of the water . I want to get all the plants growing well before I
get any more fish.
I am at a loss on how to get rid of this green water permanently. I still
need to get more plants, I have about 8 right now but didn't want to get
anymore until I get this under control.
Thanks,

Brian