ID please

[TanknTang]

Hey guys can someone please tell me what this algae is? I been fighting it forever and I do my water changes weekly and even twice a week thinking itll help. Nothing works so far. I have a skimmer, bio filtration, with filters etc. I vac the sand every week. But it does sometimes go onto the sand bed if my snails dont sift it. Any ideas im sure you guys would know Im still new. Thanks

 

[Idoc]

If you could get a microscopic pic, that would definitely help...especially to rule out dinos. Post your nutrient levels, age of tank, etc... and others will be able to jump in and help out.