How to get rid of these red stuff?

[Spyd]

Some claim blue and red Hermit Crabs will eat it, however, all crabs are selective eaters and will eat what they want, when they want...

I suggest purchasing some Nassarius snails as well. They are sand sifters. They will not eat the cyano but they will eat the left over food particles, etc. as well as stir up the top layer of your sand bed.