Root rot, or decomposition of the roots is caused by anaerobic conditions in the root sphere.
If the grow area (especially at the roots) is cool in temperature the plants don't take up water as fast and the roots choke from insufficient oxygen when surrounded by standing water.
When the oxygen becomes deficient and disorders such as Pythium will travel and infect all the plants through the root zone.
When your roots suffocate (because of insufficient low DO Saturation) the result is always the same; sick roots, dead and dying roots, roots rot, roots decay attracting and promote thriving fungi colonization. Pythium only thrives when dying rotting roots are plentiful in DWC. Some elementary school graduates can figure this out. Some of the brighter grads that are motivated can correct this anaerobic problems and prevent root rot/fungal infestations and some simply can’t/won’t.
If you are into root rot prevention, how do you do that?
This may take at least a Jr. High School graduate that passed General Science that has command of a little reading comprehension to figure out how to prevent root ball suffocation and insure that no low oxygen crisis damages or kills (suffocates) roots and or beneficial microbes. Benny’s are aerobic creatures, they require and consume O2, not nitrogen gas. One pound of microbes require more DO than might think to thrive and promote healthy colonization in res water. One pound of live microbes in solution is 1/8 of 1 gallon or 1.92 ounces of live microbes.
Of course the simplest solution that prevents suffocation is prevent the possibility of any low oxygen crisis. Provide plenty supplemental oxygen greater than 21% O2. Doesn’t really matter where the supplemental oxygen comes from, O2 tank, O2 generators, O2 concentrator, etc. The O2Grow has some serious O2 production issues that you would never know about unless you actually tested the DO Saturation while using the rig, but the sales literature sounds great as does the salesmen’s pitch… without a DO testing device - buyer beware. The little rig does generate pure 100% O2 by electrolysis of water, just very little pure oxygen and 2 X as much Hydrogen (an explosive gas).
Never be confused and mislead, air is not oxygen: more air, bigger air pumps and colder water will not insure continuous minimal safe DO Saturations, common gossip and beliefs promoted by the less educated and water chiller salesmen and forum pseudo experts and “know-it-alls” like rocket-man and his sidekick, Dip-s.
Just quit repeating the same mistakes over and over, think “don’t suffocate the roots.” Prevention dude, prevent anaerobic conditions around the roots continuously 24/7, that’s a very simple solution to the root rot problems.
Many hobby growers keep making the same mistake over and over and over failing to figure out and see the light why they root rot kills their roots and they keep catching massive fungal infestations…repeating over and over.