Start out slow with it, if you haven't run it in your system before, don't do throwing in the top amount all at once, it can shake the system up really bad. Other than that, your good.
Thanks man. I have a 125 w/ 40 gal sump (prob 150 gal total). Got a phosban 550 w/ 3X 150gram containers, each treat 150 gallons.
Do you think I should start with something like 75 grams?