On a fresh water tank???? I just filled up my 30 gallon tank(was gonna put an iguana so i bought sand for it) so now the sand is floating all over the place and the water is pretty brown, i have 2 nice big filters running but 1 keeps getting clogged
What a mess i make
In certain small quantities it is OK - but that sand is rich in it.
I would take the time to do it right. It is not much money to get the right sand.
This stuff was designed for desert animals.