Hey savage,
I like this set up and I'm excited to see your results. With that many plants you could do 12/12 from seed and get decent results. If you have room in your house, put 2-4 of them in a different room under 20/4 light schedule so you can have some mother plants. If you veg out 4 large plants you could easily fill that space once the sea of green finishes.
As far as the high tds is concerned, just make sure it doesn't build up too often. Aerate your well water, because oxygen is ionic and should reduce your TDS slightly. I would use well water 2-3 times and then buy some RO water from the store and use that 1-2 times. That should keep the soil from getting too high in calcium/lime/iron.
If you want to boost the red light, just buy some of the cheap all red 660nm panels from ebay. They are like 30$ but 2-4 of them should do the trick in your room. If you are serious about the high efficiency side of lighting, keep that plasma, and buy some nice leds once you have more money.
As long as you are feeding your plants the right food, giving them the right water, and providing them with the light they need, I see no reason why you can't get at least an ounce a plant. I'm not sure if it's your fist grow or not, but any new set up takes some getting used to. You will find out what your plants want in no time.
Sincerely,
ILovePlants