Hi. I’m sorry to hear about your problems. I’m sure it’s beyond frustrating.
I’m not a DWC grower. I grow in coco with Lotus Nutrients. I love lotus, it’s so freaking easy. Expensive though.
I do however have experience with Fox Farm. I have about $300 in fox farm nutes collecting dust. They’re difficult to dial in and I always had issues with frying my plants. I decided to give my tomato plants some fox farm this summer, you know since they were just collecting dust in a box. Yup, killed my tomato plants too.
And then using sledgehammer??? This stuff scares me. Too many horror stories. You can read stories on here. Just search “sledgehammer”
With lighting, I was a victim of the Amazon Blurples. You can read about it here.
If I were you, the first thing I would do is switch to Jacks 321 nutrients. It works great, tons of growers on here use it and it crazy affordable. Like 15 cents a gallon or less…. Much less than FF. On top of that, it’s easy.
“F” Fox Farm. I know lots of growers have success with it, but I always ran into issues. And sledgehammer…… ugh. No thanks.
Secondly, work on getting a new light. I know it’s not in the cards now, but in the near future. What you have now should be just fine for Vegging.
I hope everything works out. I’m going to follow along and be of help where I can.