On the bottle it's recommended to use 1 to 2 tsp to a gallon. I read on the GH web site to only use 1/4 tsp to a gallon. What strength is every one else using? On the feed chart it says to use 2 ml to a gallon. I've been using 1/2 tsp to a quart going by the bottles recommendation and splitting it to fit a quart of water. That could be why I'm having the problems I am.