I use it in hydro but it can be used with either. I veg 21 days to get them the height I want switch to flower on the 8 day I use a half cup of the phosophload for 3 days that is half the recommended dose for a 3rd the time any thing more than that it gives a little fert burn with the strain I am running currently. Here is a pics of the 1st grow using it with juicy fruit a strain that I was running a while back. Unfortanatley I do not have the pics to compare it to without but I guarantee it made a difference. I belive in order to show an increase you have to veg a little longer to get them the right height maybe a week. The same plants without it were a foot taller this is at 31 days it yielded about 100 gs when finished which was about a 20 g increase from the previous and like I said a foot shorter it could just be by keeping them compact more of the lower buds developed since the light could get to them which I could then use as buds instead of making hash like I normaly do but either way a plus