So for me there was a little more at stake than just trying to increase DO by using a water chiller. You see, even more over pythium, many algaes love temps over 72 degrees. You can wart off most pythium and algae with more oxygen, the problem is that algae loves oxygen just as much as your plants roots, so if algae does get any kind of foot hold in your reservoir, then pumping more oxygen in there is actually just breeding something for you plant to compete with. Ideal water temps, no matter the DO, keeps the perfect harmonious balance. That waterfarm bucket I have above, it lets light through, major mistake on general hydroponics part. If algae was to take off because I was running 75 degrees combined with light penetration, then it won't matter the amount of DO in the water, however change that temp to 67.5 and even with a little light penetration you won't have any algae problems There is a pearl white to my roots that was never there before on and off my other DWC setups. I've had setups side by side that cannot compete with a chiller and this is with h2o2 going in, doing reservoir changes to get the h2o2 out and replace it with sm90 or hydro guard, or whatever as a temporary reservoir fix. I don't use any of it anymore. No hydro guard, no peroxide, no sm90, no temporary fixes, just a simple submersible pump, some hose and the chiller. Plant growth has changed substantially and I have watched plants in soil, Coco and dwc and never witnessed the growth rates that I do with a chiller...... Now granted, I have never tried NFT or any aeroponics, so can it get greater, I'm sure it can, but in "DWC" I have never found water temperature substitutes. Also, I have gotten one plant to produce almost a pound at 78 degrees water temps, so I know this is possible, however, I feel that same plant if kept at 68 degrees the whole time would have had a better yield by over an ounce, that's just my opinion, and I'm talking maintaining those temps over the life of the grow so it's not like you can drop a frozen bottle of water into the reservoir every day.