When I used Jacks I did like they recommended, 1/4 tsp per gallon every watering thru whole grow start to finish, and I had great results. Of course I didn't give it to seedlings right away. Also I used Jacks Bloom Booster thru whole grow veg and flower. Not saying you have to do this, but it worked well for me, it was recommended in the learning section on RIU a few years back. The point was why not keep things simple, and just use one good fert through whole grow. I tried it and have been doing so ever since. Later.