iv never actualy used this before. I have always bought it from a pet store, but the other day after buying a teeny container from the pet store for $16 decided to look at other options. I did a search on canreef and see someone in alberta got some from univar, and since we had an account their i decided to order it. Im going to mix it with epson salts i think, someone posted a brand from superstore they like in another thread, might give it a try. Im hoping to eventualy get some dosing pumps to make things a little more automated. Im fairly new to all this and dont have many corals right now so havnt done much dosing but its time to learn and expand I figure.