For the size of the closet you are growing in you should ALWAYS use a 600W HPS for flowering, but the kicker is for about 162 bucks you can find complete setups that come with 600W HPS AND Metal Halide bulbs, the reflector and the ballast....
Therefore, after you have your DWC setup in your closet, you can keep your vegetative growth going with all the bang for your buck (at 140lumens) and then when your ready to flip your girls over to flowering all you gotta do is change the bulb (remember to change it with a kleenex or papertowel because the oils in your hand will easily bust the bulb as soon as it heats up).
In response to your seed growing:
1.First place your seeds in distilled water in a clean bowl.
2.Cover the bowl with a papertowel and then place the bowl in a dark place.
3.After about 24-36 hours (in complete darkness), check the seeds.
**All seeds that have sunk to the bottom of the bowl and have slightly cracked are ready for germanation.
**The seeds that are still floating (just toss them, they dont have enough of the essential acids and oils to make the long run in beginning their growth.
Next, in either a distilled water, pure water from reverse osmosis at a pH of 5.3-5.5, or (what I do!!) is to soak your rockwool fiber in "Dutchmaster Nutrients" "A.P.S"-its a ready made "mother's milk-primordial ooze" for beginning sprouts for strong growth.
**After you have your soaked rockwool fiber blocks, take a Chopstick and make a round hole in the center of where you will be putting your seed in.
(((The rule of thumb))) The depth at which you place your seeds in rockwool fiber is twice as deep as the width of the seed!! NO MORE, NO LESS!
**Lightly close the holes in which your seeds have been planted and put them in a germination tent if you have one. (Or just take a shallow but wide rubbermaid/tupperware bin) and place it upside down. This way the lid is what you place your rockwool blocks on and cover them over with the bin itself.
**Ensure you have place JUST A FEW holes in the bin for CO2 movement, but remember that you need seedlings (and clones) to be in 95%-100% humidity for initial growth and root production.
*With your pH balance for general watering you want it to be between 5.5-6.5. (But we all know that 6.3 is the BEST for the water within your growth system, but if you dont hit this number exactly DONT worry about it and dont try to fix it with pH up or pH down, just get in the area of the measurements...everything will be a breeze after that.
In getting your nutrient mixes down, look at each of the sites, many of them will have the amount that you need to add per week based off of the total amount of gallon system your using, so that is the easy part.
The hard part is remembering to constantly top off your system with the same level of pH balanced water (or whatever water you decide to use). The reason behind it is because as the plants suck up the water, the nutrients (at least some of them are left behind) so your pH balances will rise because the concentration levels will begin to become to acidic.
*The solution-get yourself a topping off reservoir that is as close to the total amount of gallons contained in your system with a float-valve so you dont need to constantly check your system.
For your smells, you could either get yourself a grow tent that is selfcontained and keeps the smell down pretty good, or you can "ziplock" your closet with a ventilation fan connected to ventilation hoses leading to a carbon filter for your exhaust. For your intake you just need a filter that will keep out dust and bugs etc...
Hope this gets ya started in away....
You got alot of reading ahead of yourself like understanding diseases and growing altogether, here's a list to get you started.
The Cannabis Grow Bible-By Greg Green
The Cannabis Breeders Bible-By Greg Green
The Marijuana Garden Saver-By J.C. Stitch
Green Weed-By Dr. Seymour Kindbud
Marijuana New School: Indoor Cultivation-By Jeff Mowta
Ed Rosenthal's Marijuana Growers Handbook
...Hope my info give you a little more confidence in getting started farmin some green, if you need anymore info, dont be scared to ask, ill do the best i can to pass on my info bro....
Keep growin!!
"TokenBlack"