Guess in my opinion, a little algae is normal! But I can understand how one can think it would be unsightly. You seemed to have done all the obvious remedies; reduce feedings, reduced the bio-load... If you notice it consistently recurring, then maybe you can purchase a pleco or school of ottos that would feast on this nuisance? They would definitely keep it under control. It would be like an "all you can eat" buffet for them!
A couple questions that may help us get to the bottom of this...
What type of filter are you using?
How many hours are your lights on for?
Does your tank receive natural sunlight?
What are you water parameters? (phosphate, ammonia, nitrite, nitrate, pH, temperature...)
Your water may just be high in phosphates, that's why I listed that first. If you can, definitely check your phosphate levels which may be contributing your your increased algae growth.
Algae needs two things to grow essentially (other than water), light and nutrients, so regardless of what you do, there will most likely always be some algae growing. The algae is likely to be kept more at bay if you own fish like plecos and ottos that are natural clean up crews.
Last edited by JouteiMike; 03-11-2012 at 08:38 PM..