Having a bare bottom I do a 15G water change weekly anyways which I hope covers most of the bases. I did get some Seachem samples of each listed to try at some point last fall. I attempted to dose over the course of a month but since I don't really have the test kits (who wants to spend that much on test kits?
) I felt that really just pouring the stuff in there blindly wasn't making much sense (even though I was following the directions on the back of the bottle). Also the dosing regimen and lack of "noticeable difference" in any of my inhabitants were a deterrent to continued use.