Well Im sorry guys, I have never done a hydro grow and am pretty ignorant on alot of subjects. But thank you all for the help anyways! And sorry Xare I did NOT mean to hijack your post, but it seemed like your questions had been answered and mine are on topic. Right now I am just finishing a white widow (omg they have taken forever) soil grow, and already have the rockwool slabs and cubes for the hydro grow next.
Hey welcome to the discussion and since it is about flood levels you are not hijacking, your adding to the discussion. Yes, I had some widows that flower for about 14 weeks, they are shown in my avatar.
So name of the game for me will be to flood my channels about once a day, wait for the channels to get full, and then unstop them sending anything non-absorbed by the rockwool back to the res via gravity. Rockwool should stay moist enough throughout the day to keep the plants fed apparently, even though im from a really dry region.
I am not sure you understand flood and drain, matter of fact I am sure you don't. You don't have to unstop anything in a flood and drain system, when the pump shuts off the water will simple drain back into your reservoir thru the pump because it will drain by gravity.
What you want to do is get a timer, plug your pump into it, lay your ph'd rockwool slab in it and turn your pump on, time how long it take to flood the tray about three inches deep, set your timer to come on for that amount of time once a day, I set mine for two hours after lights on, and then just monitor it.
Also, for the res solution, does it matter what kind of water I get? I REALLY dont want to use my local tapwater, due to it being extremely hard water and high in sodium based things (like high enough to make permanent stains in the showers and form salt rings in evaporation trays). So I was contemplating on buying my H20 from the store...
It sure does, 90% of the plants is water. IF your water quality is that bad, and you are going to go hydro you might want to consider on ro system. I bought mine for about $200.00, spend $120 a year on replacement filters, I have five 30 gallon reses to change every two weeks, it does fine. Until then it might be helpful to just let any water you use sit for a day before using it, always ph after you add your nutes, the nutes have buffers in them and will affect the ph.