Hey Doco I use it sometimes....I was using a teaspoon a gallon for algae control and when that didn't work i was told to double it so now I use 20mls for 2/1/2 gallons....we are talking the store bought 3% here....every other day. I've sort of gotten away from it because I was using the cannazym and you can't use both but I've been using it in the veg stage of my grow this round at that dose.