Phosphate problems

I have a reddish brown algae on my sand, and water changes havent helped. How can i lower my phosphates?

sorry so late but if your having red slime or algae on your sand its prolly not due to phosphates. your probably having a high nutrient level/nitrae. it could be caused by running lights too long or old bulbs. what are you running? look up diatoms check this out may help/ you basically have to eliminate whatever the diatoms are feeding off of. assuming its diatoms http://www.wetwebmedia.com/brownalgcontfaqs.htmhttp://www.wetwebmedia.com/brownalgcontfaqs.htm