My man, I’m not really sure what you have going on there. But I can make a few general assessments.
First of all, you don’t have the light there to be running plants that big. You can certainly grow a plant with cfl’s and a19 bulbs, but you need s few for even a small plant. Big picture, you’re gonna need to do something with lights or keep your plants smaller. Next, your medium looks awfully dark which is usually a sign of being wet. Without the light, they’re not gonna drink a lot. Which means you really have to be careful on how much water you give. When the medium doesn’t dry out in a reasonable time from uptake and evaporation, the water sits there. That will cause all kinds of problems for your roots. Also, you didn’t post any temp or humidity data. Do you not have something to measure that stuff?
Shit will break, spill, get lost, or whatever all the time. It really sucks when you’re new because you probably haven’t ph’d your water enough to thumb eyeball what you typically use. You can half assed avoid that by taking good notes. If you had kept track of how much ph adjuster you typically used, would probably be a safe bet to average that and let it fly. It’s a hassle and most people aren’t that organized to keep track of how much ph adjuster they use. But the more particular you are with taking notes, the better chance that they will save your ass in the future.
Based on the pictures, temp, humidity, root issues, or inability to produce the energy required could all be the culprit there. Maybe even more than one. Without a little more info would be very difficult to pinpoint what’s going on. Sorry I can’t be of more help.