For PP you mix 7 grams powder into 100ml water.That makes the solution .Each drop of the solution produces 1ppm per gallon .2 ppm is the safe dose .Never go over 3 or 4 ppm without having enough experience that you feel as confident using it as you would any de chlorinator . If it is not as simple as de chlorinating for you observe the 2 ppm rule .
Use 2 drops per gallon to get a 2ppm dose for the tank .
Water should stay purple/pink for 4 hours .If it goes yellow /brown in less you can dose again but only the one time .
After the treatment [4 hours ] I deactivate the PP with H2O2 [ 3%] at 1 ml per gallon and then change water .You can pull your bio media if you choose but leave the filter running for circulation .
You only do this the first couple times when you have time to stay and watch and always have the H2O2 or Prime on hand .
If the fish show any negative reaction to using the PP de activate it right away with the H2O2 or Prime. and try on another day .
THIS STUFF IS NO JOKE AND IT WILL PERMANETLY STAIN ANYTHING AND EVERYTHING YOU GET THE POWDER OR LIQUID ON .WEAR GLOVES ,OLD CLOTHES AND SAFETY GOGGLES WHEN MIXING AND USE GREAT CARE AND WHAT EVER SAFETY YOU FEEL YOU NEED WHEN DOSING ..mix IT OUTSIDE OR IN THE GARAGE /BASEMENT /IN SERVICE SINK ..