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.
Yea, water temp is definitely too high.. You want to remain UNDER 70, preferably around 68 but not lower than 64/65F. Ice bottles work, but not for long.. You have to change them out every few hours which is honestly a pita.. The room temp is ok, over 80 and it's gettin a little hot.. Whats the RH like? Keep in mind that it will change when the girls start to transpire (breath) in there.. As they transpire they will release moisture and change things so just be prepared for that (humidifier/dehumidifier). In terms of "free" ways to lower the res temp: 1. Cover the bucket and lid (around net pot) with aluminum tape (home depot or hvac supply house). This way the heat will be reflected and not absorbed. 2. Ice bottles - which you already mentioned 3. Cool the light with a fresh air intake if you live in the north, just be sure to filter it first. 4. DIY chiller - people make them out of dehumidifiers - I've tried myself but it's honestly not worth the effort seeing as how the evap coils that they use are made of copper/aluminum and they won't hold up to being submersed in the high salts levels in the nute solution. Not to mention the higher levels of copper or aluminum that will leach into the soup and will most likely throw off your mineral balance and just muck things up to put it simply. 5. You could also plumb the bucket to a controller bucket with the lid off (outside the grow room in the DARK) and blow a fan across the top. The evaporation will cause a considerable amount of cooling, but you'd have to recirculate it to the dwc via pumps of some sort - submersible power heads work well but again its not free, and not worth the effort IMO . . If it were me - I'd just run bottles temporarily and keep my fingers crossed during the first run, while saving the money to purchase a chiller in the near future (under $400 i believe). It's not like the second your water temp goes over 70F the plants are going to die.. Many people run a little over 70 but your chances of running into a problem are MUCH greater is all..
Thanks. My RH is dialed in at 66%. I've has success with my air temp being on the higher end. But I would really like to lower that still. I'll probably end up doing some sort of diy on my next run for a water cooler. Will 75 degree water kill my plants? Or just more prone to having problems. I'm gone 10-12 hours everyday during the week so I need something tht will last.I'll throw some tape on the lid and see if that helps
Yea you're going to want to cover the entire bucket including the lid with reflective tape.. That may buy ya a degree or two.. The problem with warmer water is that it holds less oxygen than colder, and it also helps bacteria to multiply faster.. So it's not the warm water itself that hurts the plants - it's the lower d.o (which slows growth) and the creation of a more ideal environment for anaerobic bacteria to flourish in...