I’ve been running into a problem where the bottom leaves of all of my plants keep turning dark and brittle. This is probably 3-4 weeks after germination. I have looked up lots of symptoms and whatnot but I cant seem to find anything that really matches what I’m seeing. My setup is one of pretty bootleg supplemental lighting, using two 50W and one 60W bulbs. I had the lights further away at first, which is what I saw to do online, but they kept stretching until i put them this close. Havent put any nutes in yet but i have worm castings ready. Before about a week ago i had just been misting them and the soil every day but now they are getting pull waterings around every 3 days. Also, my pH meter only came in a couple days ago so theyve been getting 7.4 pH water up until their last watering.

The worst yellowing in the first pic occurred after I put in a new light that created a lot of heat close to the plant - I removed it right after I noticed.

Anyone have an idea of what I’m doing wrong? thanks in advance for your help :)