Do you guys know where to get cheap black sand that won't harm the fish and has a grain size almost the size of pool filter sand? If any of you have used it, does it work well with MTS? Did you ever have any problems with it? Also I know about anaerobic pockets and was wondering where to get Malaysian Trumpet Snails. Also the best kind of MTS you guys use. I heard Miracle Gro Organic Potting Mix is good, and then there's also bad reviews.