seems to me that 5.8 is the perfect hydro ph...if you put an airstone in teh water you can run the drip 24/7 just like a dwc where the roots are in water all the time the roots dont need to breath air if there is a ton of air in the water. the water will get oxygenated from driping thru the air, but if your gonna run 24/7 i would put an airstone in for good measure. same thing with ebb and flow, you can run it all the time if there is enough air in teh water.