I am shortly going to be acquiring a 50 gallon tank and a pleco (along with other fish) from a friend, and I have been debating getting some Estes Marine Sand for it (its fine for freshwater), since I've read that plecos like burrowing in it. I heard a couple places that it has some sort of varnish or coating on it though, and i was wondering if that could hurt a pleco, who would presumably end up sucking on it. (On a side note, how do plecos not end up eating sand?) It seems like a good buy otherwise though, its heavy, not sharp, comes in black, is pretty clean, and is 36$ for 60 lbs.