Ive read that even in low light tanks CO2 is beneficial. How much CO2 is needed in a lower light tank, say 90 gallon with 96 watts of t-8 light? Is it still 30ppm?That light is very near being high light intensity, where CO2 is essential. I would use CO2 anyway, because it lets the plants grow at the maximum rate the light will drive them to grow. If you raise that light 8-10 inches above the top of the tank, the intensity will be lower and more uniform in the tank, and then you really won't need to bother with CO2.
What do you mean in these sentences? I lost ya....However, I doubt that 3 x 32 watt T8 bulbs will give even low light on a 90 gallon tank. But, that might be ok.
I know its been a while since this thread was active, but Im now finally getting around to getting the 2 X 54W light fixture. What ferts do you dose in your tank? Any algae issues? Are you using ro water?I agree...I have a similar setup over my 90 and its fine. I grow only low light plants though and the tank is low tech.