Yeah, using it on this grow of mine now. I only tried it because of the recipe I was following. It said to use something called Kool-Bloom Powder but we cant get that in the U.K - I searched for a while and found out this Grotek Monster Bloom is similar.
Its good stuff. 1 level tea-spoon per 20L of water - Makes your water go purple
As soon as I started using it, I noticed the plants started packing on the weight pretty quick. I stopped using it a week ago as the instructions say not to use it for the last two weeks.
Its difficult to say if its better then anything else I have tried because this is my first time in hydro
you can see some of the pics I have grow using it
HereStay Cool