Thanks for the tip. Will strongly consider.Go with diamond black blasting sand it is the same stuff. Make sure you get the larger grain version Tractor Supply carries the stuff. It is $8 for a 50lb bag.
There are different grain sizes they are marked on the bottom of the bag. The largest being about the grain size of flourite black sand. A hair bigger then pool filter sand. Definitely stays put and doesn't float around. I have a 1050 gph powerhead blowing directly across a patch of the sand on my substrate to keep it nice and clear and it never knocks particles lose. Doesn't compact at all even the smallest size. People don't realize compacting happens when you have several different sizes as they all fit together kind of like a puzzle. However when it comes to a substrate that's particles are all the same size they will not compact.Is it large grain? I need large grain to keep it from compacting. I've also heard sand blasting sand is sharp, I have at least 20 corydoras and a 7" Synodontis so...