I think perhaps you mis-interpreted, or perhaps I wasn't clear. There are basically two paths to go, beni or not. There are benefits to using beni's in the form of increased nutrient uptake,resistance to bad bacteria, etc. Its a balance between good and bad beni's. One that you don't have much control over really. The bad fungus and bacteria really start to bloom above 70 degrees..so they might overwhelm your good bacteria.
The other root is a "sterile" rhyzosphere. You add h2o2 every3-4 days in small doses. There are no fungus, bacteria, etc in the root zone. It is a fine technique but kind of misses the point so to speak when using organic nutes which end themselves to the complex interactions of breakdown and absorption between fungus colonies and root structures. H2o2 also adds oxygen to the water for plant uptake but it breaks apart and dissipates rather quickly, hence the 3-4 day maintenance doses.
A warm liquid inherently has less ability to hold dissolved gasses. (ever drink a warm soda that was also really fizzy? no you haven't as the co2 has come out of suspension). So if you water is warm, there is not much you can do to increase oxygen levels and oxygen in the root zone is CRITICAL.
My water temps have been hitting 75 so its time to do something about it. The chiller I am going to make is thus..
Craigs list window air conditioner =$50
50 feet of flexible 1/2" copper coil =$80
some 1/2 rubber hose
35 gallon container
smalll water pump.
The airconditioner is placed directly above the container filled with water. The shell of the air conditioner is taken off and the cooling fins (that the air passes through in front of the AC) are carefully bent down so they are sitting in the water. Therefore the AC is now cooling the water in the container. The copper coil is placed in the cold water and a small pump in your nutient rez pumps the water water through the rubber hose and through the copper coil (which is now cold) and back into the rez. Boom, homemade chiller.
Works on the same concept as one of those mobile keg Chiller cooler things. The warm beer passes through the cold copper coild in a cooler full of ice...instant cold beer. And who doesn't like cold beer?
The dopest of dope ways to do the same thing would be to bury the copper coils about 10 feet in the ground and use the cool earth to coil the water but I just don't have the time to do that and you would likely need more coil as earth is less conductive of heat than water.
ok? ok.