It's a subcools supersoil sucks kinda thing. Nothing is available in that soil until like the 2nd or 3rd time using it. And even then it blows IMO. It's a lack of micronutrients causing that yellow.
Had the same thing happen everytime with subs ss. Especially the first 2 weeks of flower. I upped the calcium and foliar sprayed with maxicrop plus iron and the plants were back to a dark healthy green in about 5 days.
Atleast a 3 ton. The DE run a lot hotter than a standard bulb. I would not even try to pull fresh air, you're simply making too much heat to cool it. Id go with 2 2 tons, across the room from each other. This gives you a chance if you have a A/c failure, because the other will keep the room...
You will be blown away by it if you have always air cooled. Keep a oscillating fan right around bulb level and it helps disperse the heat throughout room. Run a mh the last one to two weeks. I like the 10k finisher spectrum for this. The density and resin it produces is outrageous.
You really wanna calculate at 5k btu per un air-cooled 1000. That ac will run close to constantly during lights on, which will keep your humidity low during lights on, a blessing in flower but a curse in veg.
My secret is to change clothes and shower, after being outside,before you go into your garden. Especially if u worked on outdoor garden, cut the grass, went for a hike or any other activity that could contaminate you.