Help identify and treat please

[oxy71]

I have 4 month old tank. This stuff is hard to scrub from rock. Lays on sand, thick. Comes up in clumps. Parameters are good but I heard nitrates and phosphates are low because this stuff uses them for food. Thank you

 

[shakacuz]

difficult to say, but very likely green hair algae. manual removing and adding more critters to buff up your clean up crew (astrea, cerith, trochus, nerite snails). hermit crabs like red leg or blue leg help a lot too!