This is a good product but keep in mind that if you do not find and eliminate the source of your problem it will just keep coming back. Using it easy...one spoonful for every 10gals of water. Mix it up in a glass with some water from the aquarium and dump it into the sump. Make sure you turn OFF your skimmer and remove ALL forms of chemical filtration (GAC
, etc.) and any filter pads. Wait 48hrs and do a 20% PWC
. Repeat if needed.