lighting for a 82cm deep tanks

[peteg]

Hi all

I have a 220l custom made freshwater tank, the dimensions are 82H 79W 34D, i have attempted to grow plants in it in the past with little success despite having a CO2 system, and plant supplements. I think the lighting is the problem i as not enough light is reaching the bottom of the tank where the plants are.

Does anyone know what sort of lighting i should be using to grow plants in a tank that is 82cm deep? any sort of guidlines on depth-wattage ratio

thanks very much for your time

Pete

[smaug]

metal halide or halogens will be about the only thing that will give decent light to the bottom of such a deep tank.200 watts would be about minimum.