I've read the forums about the causes of green water... too much nitrogen seems to be the consensus. I am beginning to think that, in my case at least, CO2 may be the culprit. Let me explain...
I have a 75g and a 20g planted tank. The 75 was always a lowish light setup, with 120W flourescent, a sand substrate, and some light plants. I tried adding lights, but had a serious problem with beard algea, and took off the 130W PC light I had added.
Then I got my 20g. I set it up with eco-complete and the big PC light. I had some algea problems there too (i thought it was a 30g at the time... it's an extra tall tank, so I don't know about the light ratio). I figured adding CO2 would help the plants grow much more quickly and help combat the algea as well.
Within about two weeks I had a major green water problem. First I tried adding more ferts, then less ferts (after blackouts). I tried turning off one light. Nothing could fix the problem until I tore the tank down (it's still empty). I blamed it on the eco-complete, seeing that they've had some problems with this.
Since I had a pressurized CO2 system, I decided to install it on my 75G tank. This tank has been a very low nitrogen system... always less then 5ppm Nitrate if I'm not dosing. Other then the beard algea with the doubled light... I've also never had an algea problem with the tank. Within about three weeks though... I have a serious green water problem on my hand.
I did 3 back to back 80% water changes, along with scrubbing everything down and vaccuming everything possible, and didn't even feed the fish, but less then a week later, the GW is back.
The ONLY thing that changed in the tank is the addition of the CO2. I just shut it off and am going to try a massive water change again, followed by a blackout and see if the problem recurs again... but I figured I would share my hypothesis and see if anyone here has noticed anything similar.
I have a 75g and a 20g planted tank. The 75 was always a lowish light setup, with 120W flourescent, a sand substrate, and some light plants. I tried adding lights, but had a serious problem with beard algea, and took off the 130W PC light I had added.
Then I got my 20g. I set it up with eco-complete and the big PC light. I had some algea problems there too (i thought it was a 30g at the time... it's an extra tall tank, so I don't know about the light ratio). I figured adding CO2 would help the plants grow much more quickly and help combat the algea as well.
Within about two weeks I had a major green water problem. First I tried adding more ferts, then less ferts (after blackouts). I tried turning off one light. Nothing could fix the problem until I tore the tank down (it's still empty). I blamed it on the eco-complete, seeing that they've had some problems with this.
Since I had a pressurized CO2 system, I decided to install it on my 75G tank. This tank has been a very low nitrogen system... always less then 5ppm Nitrate if I'm not dosing. Other then the beard algea with the doubled light... I've also never had an algea problem with the tank. Within about three weeks though... I have a serious green water problem on my hand.
I did 3 back to back 80% water changes, along with scrubbing everything down and vaccuming everything possible, and didn't even feed the fish, but less then a week later, the GW is back.
The ONLY thing that changed in the tank is the addition of the CO2. I just shut it off and am going to try a massive water change again, followed by a blackout and see if the problem recurs again... but I figured I would share my hypothesis and see if anyone here has noticed anything similar.
