Lots of research on genetics, determine what strain to grow.
Here's what I would think to do, if I was starting from the beginning, with a budget.
Seeds; $50-100.
Tent or reflective white roll; $85-120, doing two closets, just do some research to decide on that.
Venting (two intake, two out fans, ducting); $100
DWC bucket system; $100-250 depending on how many to fit your spaces. I've done the math for diy vs premade, just find a great kit on amazon and read reviews.
8 bulb t5's ; $150 each plus extra bulbs, the one I got came with 6700's. Check out eye hortilux line of powerveg, their site shows how to setup the bulbs for veg vs flower.
A PPM meter and a PH meter; $25 for cheap ones.
that's probably more than 800......
ph up and ph down and grounded timers and fans....
Pick a basic nutrient line, like general hydroponics 3 part. I went with the Lucas formula instead.
You'd use CaliMagic as directed, the gh micro and gh bloom in a 6:9 ratio. Look up their feeding charts, mix up calmag first, then micro, then bloom, then check ppm and dilute to the lowest recommended amount for that week, then adjust ph.
This basically maxes out your 800, maybe even goes over.
hid's will get way too hot for closets without buying air conditioning, plus the increase in electricity cost (mine tripled with only one light). and led's are cooler but higher initial cost.
You don't have to buy everything all at once. Figure out the strain, buy seeds. Then set up the closets with either the tents or paper and ventilation.
You might not get the seeds for a few weeks as they're usually coming from over seas.
So then buy the ph stuff and some rockwool. Learn about germination/propagation, check out harley smith's all about cloning video, it's like an hour long but the seed stuff is only part of it.
The seedlings don't need nutes or even 400 watts until they have true leaves, so you can just start them and then buy lights and nutes. The cotyledons will be fine any daylight bulb at 24 or 18 hours. You get what I'm saying?
