I don’t see anything wrong with your roots. A little staining is normal. They don’t look slimy in the pics, do they look slimy to you? Smell them, they should smell good, kinda fresh.
Your 130 ppm water might not be a bad thing. Mine is 55 ppm and I’m getting some pretty good ph swings on powdered nutes (Jack’s 321). Next to no carbonates in my water. Your’s is on the high end for hydro BUT it might be full of carbonates and calcium.
How often do you change out your reservoir? If it’s often then I doubt you need the chlorine at all.
You’ve got a few things going on here, maybe it’d be best to simplify things a bit. I don’t want to fuck up your plants but here‘s what I’d do. Dump and mix a new tank. I’d take
@tehdansauce ’s advice and cut that P number. Can you drop the B part of the nutes so you get closer to the ratio he mentioned. I’d skip the chlorine and h2o2 for this tank.
I think all you have is an issue with nutes. If you have another line that you’ve used before or want to try out this might be a good time.