This stuff is just rediculous. I do 1 quart daily water changes on a 60 gallon. I bought a box of this because it's what the store had instead of the usual TM. I did my first 1 quart change last night, I wake up this morning and it's like the polyps on my SPS have developed superpowers. They're all much larder, fuller, and probably because of this, more active in the current. I thought all those people writing about the difference this made were overhyping... Until today.