whats up BR69...
ebb & flow is a goo system... works great for me
- i like the hydroton, because when i want the water out i like it to flow out... rockwool holds too much water, too long for a quick ebb & flow system... they slow it way down, IMO...
my flood frequency... using hydroton, is flood on the hour, every hour the lights are on... so 18 floods a day in veg, and 12 in flower... it takes about 1 minute to flood my planters, and probably about 2 to drain... its quick, and it works well for me... i know some would say thats too often, but the girls love it
nutrients, i would say go General Hydroponics - they are just so easy, and they grow nice plants... i've tried advanced nutrients, the $800+ bill for the nutrients for a grow is ridiculous (50 gal res) - they grow nice plants also, but not an extra $700 or so (for me).
I also like to use CalMag Plus which is a calcium and magnesium additive... I use the Lucas formula on the GH nutrients, and i've run into mag deficiencies just using the micro and bloom formulas. Also, get some kind of biological growth inhibitor - like hydroguard (but i think they changed the name of that to something else, cant recall)... and that should do it.
not sure of my PPMs... i dont bother to even check them anymore...
i'll be adding co2 sometime soon - but i'm using a controller/sensor to put it right at 1500ppm (not timed)
hope that helps...
peace