to answer your question, just mix up your nutrient solution in the resivior till you hit the ppms you want by testing it with your meter

now for lights, i dont like flouros, i started with flouros way back in the day and was never satisfied with the result but there wasnt any cfl when i was growin, i do however own a sunlight supply 400watt cfl which is awesome for my seedlings and clones i would recomend if you have to use flouros, if anything dont go cheap in the light department, if you must try lookin into like a 250watt hps for when you flower and use flouros for veg, i'm tellin ya it takes so long to flower with flouros, your looking at like 4-5 months for your entire grow depending on what lights you buy apossed to 3 months with hid's, look on ebay i'm sure you can get a nice deal on a HID and heat isnt an issue, lets say you had a 250 watter all your really gonna need is a regular house fan blowin your plants to keep em cool, but definately look into a good light system