Poor air circulation due to being planted WAY too deep in much too large pots.
Must run ventilation all the time.
'Grow bulbs'= ? Not incandescent I hope. Those are all heat and few useable lumens.
Something's screwy with your soil, or it could be from heat stress. Those plants are severely deficient or locked out. The yellow leaves and red stems scream HUUUUNGRRRRRRREEE. Check the pH of your runoff.
Actually, stressed that badly, those plants are quite likely not going to flower the way you would like- possibly even turning hermaphrodite. Read the entire thread linked in my sig, plus the 'why should I repot' thread in the FAQs, for some basic considerations and I'd suggest starting new seeds in more appropriately sized pots. Oh- and only one seed per pot!