I'm starting my first dwc grow shorty. I finished setting up my room and started a dry run. Lights, fan, pumps, etc etc. room temp:76-81 F Cool tube 400w MH 240cfm exhaust into the attic Black bucket and 6 inch net pot empty. Temps of the water sit around 74-75. I would prefer to not put more money into my set up right now. I'll probably end up tossing ice bottles in the buckets. Is my water temp too high?? Everything I've read points to yes. I heard at 80+ causes rot. I've also heard 70+ causes rot. Which is the correct answer?? And Does anyone have suggestions to lower my temp? For free.