It's been 9 days and I'm holding at 28" from substrate.
I've gone down to 1 hour of burst 4x39W and 7 hours of 2x39W. I am at 4bps CO2 - I need to clean my inline diffuser before I drop the lights further - It's producing occasional bubbles and it's been 8 months since I cleaned it. Once that happens, I'll get better CO2 diffusion and I'll feel comfortable dropping the lights more.
Currently I've noticed a fine mist of hair algae on the glass after a week. I normally have very little visible algae on the glass after a week. I'm weary of dropping the light further for fear of a algae bloom. I trimmed the hair grass, which seemed to be growing thicker. I'm going to wait a week to see if it's any thicker coming back.
If the grass is growing thicker (albeit slowly), I may not need to drop the light further. If not I'll drop the light another 3" (to 25" from the substrate) remove the burst and keep it at 8 hours 2x39W and adjust the CO2 accordingly.
EDIT: When I trimmed the hair grass there is residual algae at the base (It's been there since the very first algae bloom) - I have a feeling that it may be the keeping the hair grass from growing thick...
Last edited by sundragon; 11-20-2012 at 04:21 AM.