brown algea on sand, also beneth sand

i seem to be getting a lot of brown algea on my sand, and i notice there some beneth the sand(i can see against the glass). i try to vacumm it up but i vacumm up all my sand. theres some fish poop under the sand and when i try to vacumm that up i end up vacumming up a lot of sand as well. the inverts i have are sand shifting star, 7 blue legged hermits, and 6 snails. i have a 20G long. so heres my questions

how od i get rid of the algea?

how do i not vacumm up sand?? if i cant, do i replace sand with new live sand?



thanks!!!

 

Don't vacuum up your sand, period. That's what your cleaner crew is for. You should have several nassarius snails and conchs to take care of that for you. You really shouldn't be vacuuming your sandbed in a reef tank.

The brown algae is diatoms. That's totally normal in a new tank. It's especially common if you use tap water. You will just have to wait out the diatom's cycle. There really isn't anything you can do about it.

A sand sifting star is not a good idea for a small, young tank like yours. It eats the critters that live in the sand. In a young tank, you won't have those critters. It will starve very quickly.