If that's this light:
https://californialightworks.com/products/solarxtreme-250
It states it's actual draw is 200 watts, and you need to hang it between 12" and 18" over a 3' x 3' area for you plants to get the advertised 500 to 800 ppfd. It looks like you have the light higher and covering more area than that. This would make your plants stretch and grow weak branches. The lowered levels of light would be only one concern though.
Plants grown to 3ft of height in a potting mix should likely be in 5 gallon or more pots filled nearly to the top with soil. Fox farm soil has nutrients to last a while, but does need top feeding later on, there are other posts about methods to grow in fox farm, I am not experienced with it.
I only questioned your drainage as those looked like DIY pots and I wondered if you drilled enough, or large enough holes. If the soil is loose and it runs through and dries out nicely, I think that's OK. You just need more soil it looks like, these plants might be root bound which could also explain some of the look.
I think you have a tough road ahead to try re-hab them. I would either pick your best plant, scale back to a 3'x3' area and try to re-hab and care for one plant, or start over in a 3'x3' area with one or two plants. If you start over, you'll probably be further ahead with better healthier plants, then you will if you try to re-hab these.
Thanks!