@ rkymtnman;
so just to be clear, roots get oxygen from the water that you use to feed plants in coco. glad you finally came around to what i've been saying.
i'm surprised people actually pay you for your wealth of knowledge.
Cough is correct. If you put a fish in collected distilled water it will die of suffocation. It's the O2 diffusing (diffusing is the operative word here) from the atmosphere into the H2O that provides the available O2 for a fish to breath. The O2 that's in H2O is a bonded, stable molecule and that stable H2O is not a free provider of H or O, it takes an external force for example, electrolysis, to release either. The reason people use O2 bubblers in their aquarium is to saturate the H2O with oxygen to give the fish the O2 they need; the surface area of the air on top of the water in a fish tank being insufficient to diffuse enough O2 into the water for the fish to live.
Along with the above; water coming from far away through pipes or coming up from underground as from a well is depleted of oxygen, that's why the aerator in your sink for drinking water and why an airstone provides available O2 to the water we use.
Coco's inherent air pockets are another advantage to using Coco as a medium: Coco needs to be watered more frequently than soil as coco does not retain as much water as soil. If you water in a timely fashion the plant gets the benefit of coco's air pockets supplying O2 to the roots without drying out the roots.
Too many people on here with an attitude is not a plus. Attitude is a turn-off and disservice to everyone.
My 2 pence