DWC grow i dont have seeds yet but i will soon and i have a few questions

Alright I am going to be doing a dwc grow and i am going to be doing one monster
in a dwc 5 gal bucket from StealthHydro.com and i have a few questions

1 - Would a 400W hps and 400W Mh with a switchable ballast
about a W8'xL2'x6'H and i am wondering how much ventilation ill need would a 16" round oscalating fan work?

2 - what kind of nutrients show the best range of growth in sativas, And dose it have a flowering nutrient?

3 - If I am in flowering and using nuets when should i stop before they get in the buds

4 - I also right now have a blueberry kush autoflower about 5 or 6 weeks into flowering and buds are getting to look bigger they already are bigger than a quater i dont mean a sack ethir >.> but shes 30 " maybe a little higher is their anything i want to do shes on a 12/12 timer with 2 100w cool cfl 97 to be exact and one 400w light idk what kind it is but it puts of a bit of heat and i can see tricromes all over leaves and buds some buds have red hair some are more white and alot of them are mixed

that is all please answer these feel free to hear about the grow on my new one

Gotta read and do your homework, Bish.
Copy/print any info you feel you want to retain.
Nutes work for all phases of growth. Read about NPK.
Multiply your LxWxH (2x8x6) = 96 cubic feet
Get a 6" or 8" fan for extraction. Do passive (vents/holes) intake or active (using a fan) intake.
That 400w is plenty and penetrates up to 2ft, so keep the plants short. Flower at 10 -12 inches tall from veg.
Don't stop nutes until 14 days PRIOR to harvest.
More Nitrogen during veg. More Potassium and Phosphorous during bloom.

You gotta go do homework now.........................