I recently got some snails for my aquarium and I added some Manna Pro Oyster Shell to boost the calcium for them. After it was in there for a hour I noticed something reddish orange bleeding into the white sand I use as substrate. After the MTS were in the tank for a week I did some routine maintenance and I discovered some slimy globs of what looked like raw chicken stuck to my driftwood and attached to the hornwort. Could this be from the oyster shells? I also have a 10 inch sailfin plecos and 4 mystery snails in the tank. There is also a small ramshorn in it that hitched a ride with some plants. Any ideas or help would be really appreciated! I don't want to put more oyster shells in the tank if that's what's causing this to happen.