This was growing on a couple rocks in a non lit sump tank. is it a sponge? not sure if i should be concerned. also another rock has something i couldnt get a picture of it but it was in a smallish hole and was streched 2 or so inches to another rock its grey brownish and retracts to its hole if you disturb it i couldnt get ahold of it to remove not sure what the heck that was either any ideas?
