red alge growing on the sand bed with bubbles under it

[trueplayer]

i have a 100gal reeftank and 90p of rock and 90p of sand and im getting red carpet stuff all over the sand bed with lots of bubbles under it is this bad and can i cure the problem

 

[teog]

It sounds like you have red slime with bubble algea. This is associated with high phosphates. Have you tested for this yet..