Why did you add all that Epsom salt?
How much superthrive did you use?
20-20-20 is incorrect for any life stage of cannabis. At 1/5 dose, you have a 4-4-4 fertilizer with too low levels of micronutes. You need a set of cannabis specific ferts. In soil, you have more wiggle room. In hydro, you don't.
Move that fan AWAY from the plants, and point it away from them- it's drying them out. You can see leaf edge curl.
What's with the light cycle switches? Is it possible to maintain dark period in your grow space?
Put them back on 24/0 light. Never flower a sick plant. It will more than likely die before harvest. And 5 nodes is much too small to flower a from-seed plant. You should wait for sexual maturity first. I find that happens around 8 nodes. You'll have to wait and see.