is my setup ok?

[pooldude]

well heres what iv'e got .my area is 8 sq.feet i have a 400 watt mh light..i'm using the 11 plant ebb and flow setup with 2 air pumps 1 stone is inline and one is in the tank..walls are lined with foil dull side out..50 cfm bathroom exhaust fan in ceiling and a 6 by 12 in. vent in the floor.12 inch oscilating fan.also i'm gonna use a hps conversion bulb for flowering..thinking of starting flowering when the plants are about 12 in...i know thats a lot of plants for such a small place but with my other attempts about half my plants were males..so i figure 5 will be ok..i'm germinateing my seeds in rockwool cubes with a 1/4 strength mixture of IONIC 5-2-6..soon as i get my first set of fan leaves going i'm putting it into the hydro..with the same 1/4 mixture for the first week and then bumping it up a 1/4 every week till full strength.also will keeping my PH.around 6.5 to 6.8 be ok?..my pool chem test kit won't go any lower...and how far away should i keep the light to keep from toasting my plants..1 more question before i go,how often and for how long should i flood these things..my medium is geolite...

P.S.i want to thank everyone for the input i think iv'e got the situation by the balls.i just want to know if everything sounds ok with my setup.