My reservoir temperature it's around 80F in the DWC
In my hydro tower I run it with more temperature without problems, but the aeration in DWC is worst
Temperature is a catalyst. So at 80+ your bacterial, fungal, viral and algal populations are proliferating fast. Chlorine is a plant a nutrient and why I used Bleach (in the form of Calcium Hypochlorite -- Ca is also a nutrient) in my recirculating reservoir) as opposed to Sodium Hypochlorite (which is a competitor). You can buy Pool Shock (Cal Hypo) at any pool store. That's my experience and what worked for me in the Mojave Desert where I would run up to 105 canopy temperatures and still make it to harvest. Although at times it was a struggle. I use Great White with my Coco and went to Coco because of my extreme temps here. The Great White works well for me as an adjunct although I still run a clean reservoir
@amneziaHaze has experience I don't; DWC. For me running less than aseptic in NFT caused blocking of my sprayers. So I'd say their way is worth a try every bit as much as mine. Essentially you'll learn what works for you in your environment. This is how we all learn, trial and error and we all kill our fair share of plants along the way LOL
So enjoy the journey and choose your solution and then look for the plant to grade your performance (most of my plants graded harshly LOL). Best of luck whatever you choose and I hope you can get this sorted. I look forward to seeing your plants thrive.