In my 75 gal
tank I have two yellow tails, two clowns and 60 lbs of live rock. I got 12 margarita snails to other day and everything was fine. I went to the store this morning and came back about 30 minutes later and there was red stuff, looked like rust, all over two of the live rock and the power head. I had seen trails of the same on the sand after I added the snail and though nothing of it since my tank reading were the same as before I added the snails. This completely covered the top of the live rock.
What the heck happened?