Synthetic nutes are prob your best bet cuz of the miracle grow soil. Building a micro herd or organic may take too long at this point. You are flowering so use high p with mag if or calcium depending on your water source.
Oh yuck. High P sux for flowering pot. Tomatoes love that crap but pot does way better with higher K than P.
@Levi Bruce I'm spanking your ass now for your choice of soils but like an ignorant child you have the potential to grow out of it.
You are going to need some form of better lighting to get any decent buds. Even a 150W hps security light will do better than nothing. I'm just building an 11 bulb LED rig with old vanity fixtures I scrounged up for a few bux at a local thrift store years ago. A recent promotion was selling 5000K and 2700K 9W LEDs for a buck each so I bought 3 dozen. Easy to pop the globes off to make an el-cheapo LED fixture for vegging a whole DWC tub of plants or just a few babies. Here's the basic layout.
The black lines are where I'm going to bolt on some aluminum angle iron to hold it all together. Would have done that today but crashed my car going to town to get more vodka. Nothing serious but broke the back wheel going into the ditch back-asswards so the wife had to come rescue me in the old F-150. Not the first time for either of us.
$11 for the bulbs and maybe 11 more to put it together. Good enough to veg a lot of plants or one full tub doing DWC.
Ain't gonna be pretty but for under $30 why the hell not eh!
I already popped the tops off all the bulbs I need and painted those nasty probes in the centers of each with liquid electrical tape so I don't get nasty shocks off them. Hang on and I'll get a pic.
I used a marker to write the K# on each bulb so I don't have to squint to know it's light output. These are 5000K which is just about the same as a summer sun. Got 2700K ones to mix it up a bit too.
Those little buggers really throw off a lot of light with the globes off!
These are all 9W/60w equivalent bulbs dirt cheap because the province, Alberta, is pushing them to replace the last great power saver CFL bulbs. If you see that and have a few extra bux buy all you can right away as they normally sell for about $5 each. The 100W equivalent ones are $15 for two at the store today.
My main flowering bulb is a 1000W Hortilux I bought last year for $170, Over $225 for the same bulb last month. That's just a bulb! Picked up a used 1000W MH/HPS ballast for $70 and two cheap brand new Chinese Super HPS bulbs for $40 each this last trip. Only need one at a time so got my ass covered in case of a break down.
Lots you can do to grow pot on the cheap. Once you can supply your own needs the money you save not buying pricey pot can grow your grow room.
Good luck and good growing!