General Hydroponics in First Soil Grow

Hey guys, first post! or well first question.

I have 22 day old guys in 3 gal buckets. average size is 5" I have a couple that are nearly a foot and a few that are just wee little fucks so far. Already fighting bugs. Should have them gone in another 8 days.

I am using Promix HP and the PH on it was LOW to start with which I noticed after planting (remember first shot) I also over watered a tad 3 days after transplanting which was done at day 16.

They are double or triple the size the the last 4 days.

61 plants under 2 x 1000hps. The lights are at 7' right now off the plants.

It is just about time to water. I have 100 litres of tap water that has been sitting at room temp with a bubbler in it for 6 hrs.

I have a sump feeding a garden hose to an aerating head with which i will water. I have mixed 33ml of GH Gro Micro and Bloom each into the sump and ph'd at 6.7 as the soil was low I want to adjust slowly.

Is this too much nutes for new Soil on the second water?

The first water had a very weak dose of LiquidKarma.

How much GH product should one use in soil?

PPM from tap is unknown (way over budget already).

Is it time to feed yet? with a moisture metre I am on the virge of dry with every pot.

Do I water each pot 'till it is saturated? or should I try to measure out a certain amount for each pot?

Thanks for the answers. Don't wanna kill them all for a stupid newb mistake.

Anyone? I need help guys.