I use bushmaster and gravity.

So far I use the less amount over more time for both.

Bushmaster
1-2 drops per gallon at full ferts on the 5th 6th and 7th day into flowering followed by a res change.

gravity
Starting on the 6th week into flowering add a few drops into the res and repeat until you have achieved 3-4 drops per gallon over a 14 day period. I lower my ferts by 20% and add more sweet then any other additive. My lights stay the same as well as my temps. 85 degrees with co2.

I like using less of this stuff over more time because it does stress the plant. drops per gallon are an easy way to use this stuff without having to mess around with your fert schedule.

PS. a light spray of bushmaster,penetrator, and reverse in a foiler spray is a great combo too. No seeds at all.