HELP I need info on sponges PLEASE

[BC564]

sponges are great.....you get to benefit from their filtering and require really nothing from you.

[bv_reefer]

I have a bunch of hitch hiking ones on the bottom of one of my rocks, it seems that the only places they grow in my tank are where it's complete shade, they grow like mad though (pink ones especially), i never bother feeding them or anything either.