Hard algae growing on sand???

[salty jeff]

I'm starting to get this kinda hard dark greenish algae (I think its algae) growing on my sand. I can get it up by using my net and sift it. What is it and how can I control it?

 

[salty jeff]

I think it could be phosphates because I use tapwater for tank top off. As of this weekend I will be changing that. I'm also wondering if it could be my circulation? Are their any supplements I can add to stop it?

 

[salty jeff]

Thanks Kip.

 

[clarkiiboi]

I battled that too and have won finally. I did as stated above, reduced my nitrates and phosphates, by changing from tapwater to Distilled, I dont have a RO/DI unit yet. Instead of netting it, get some air line tubing and syphone then start with the better water for tap offs and changes. HTH.