Light issue or nutrients

So I had given this 1 cap per 3 gallons of big bloom from fox farm a few weeks back. This is on a DWC system. The next watering it was given fresh water when I noticed a few leaves yellowing toward the top to slightly brown tipped. It continued to get worse even with another fresh water flush. I have it in a tent now and you can see that the lower areas are greener. Can the plant survive like this during flower and was it something wrong with the nutrients or more likely being too close to the lights. Lights initially were closer than they are in the tent. These pictures are taken 3 1/2 to 4 weeks after initially using the big bloom.

That’s not light. Tell us about what you put in your tank. Ppm, ph, mixing ratio, source water, etc.

How are you roots?
Any. Dead Leaf matter fall into the reservoir?
Lift up your plant and run your fingers gentlyish through them to see if any Roots fall off( preferably with sanitized gloves or hands washed with bleach and thoroughly rinse)

Experience looks like not enough oxygen or your pump stopped working and then turn back on and you didn't do a Rez change water. Anaerobic.... anyways it's dwc completely switch out the water clean the container if its only one you have new res freshly pH Hydro nutrients you'll be all right, not really. Definitely going to affect quality and quantity of harvest even if it comes back

Lights and power shut off during the hurricane. I will switch the water out fully today and start fresh. It does have an air stone in there. Thanks