RDWC DWC water temperature range and associated problems


Some folks claim that 62F is the ideal water temperature for DWC pot grows and temperature above 72 F will cause a lot of unnecessary problems. Water chiller salesmen say this too.
Some problems are necessary and some are not necessary, i.e. colder water (hypothermia) slows metabolism, warmer water (hyperthermia) increases metabolism.

QUESTION: Just what are these “unnecessary problems” that’s actually caused by water temps >72F?


Bacteria, slime, and not so good fungus that suffer your root system…


… and a potential for increase in bug population with a faster reproduction rate.


Bacteria and slime are normal in DWC water, the only problem I know of is Bacteria and slime stop up bubble stones quickly, buy more stones and the operational cost increases. The solution to that problem is “buy more bubblers.”

Fungi clean up dead rotting organic matter, are ubiquitous, they do not colonize nor attack healthy plants, healthy root systems or healthy bacterial colonies unless the roots systems and bacterial systems in the DWC are sick, dying, dead and decaying.
Fungi are opportunist, sick and dead roots present the ideal opportunity for fungus to colonize and thrive.

Do you believe that roots systems and bacterial systems begin to get sick, die and decay when DWC water temperature exceeds 72F? And that’s the justification for the chilled water and cost of water chillers?


All what he said that’s why :question:


Appreciate your input… thanks for responding.


Actually the addition of enzymes reduces need for stone replacement and I can’t recall replacing a airstone during grow after occasionally yes but to salvage I usually just clean stones after grow then soak them in bleach followed by h2o2 after grow for several days to clean them. I also run higher pressure air pumps which deter buildups. My res temps are kept closer to 68f at all times and I change res regular if you are running larger res it takes days for nutrient solution to warm up into 70’s and a simple ice pack can reduce temps fast. You can also consider such things as color of pots light infiltration paint black lines and pots white keep main res outside of grow space away from heat. All pro active and cheap simple prevention and control solutions


Cheep is Champ… I like “cheap” too.


Hey all new to page.

I get the water temps needing to be managed. I’ve been looking in to this bubble bucket system for a little bit and thinking about trying it out on one plant as a test run.
The main reason for me wanting to switch is cost and space. Most what I have seen for bubbles does not involve a res but seems to maintain temps one is needed with a chiller.
My veg tent sits at 82 degrees and water in test bucket with air (no stone just hose bubbling) is holding at 72 for over 24 hours. What other methods people got to keep water chilled in a closed set up. Anything more then a ice pack every so often? If 72 is as high as the temp gets will it be ok? Flower room temp is kemp 65-73 so at that stage be no worries.

Any help is much thankful for.


You can offset water temps to a point up to about ~78 degrees by pumping enough air into the reservoir that it looks like a pot of water at a rolling boil. There are also reservoir additives that will help combat root rot brought on by higher reservoir temps.


Well I pulled the trigger on my tester plant and not sure she is liking it lol. Little shocked see what she looks like tomorrow.