Product review (2 stars): Better than 90% water
The directions call for a capful for every gallon but if you want to avoid algae you probably need five times that amount. the vast majority is inert It could be delivered in a 4 ounce bottle and it still would be mostly water but at least would not waste so much energy transporting water around when it's useless, they need to add anti foam agent into the mix because of all the bubbles it causes if you added in the beginning.