Just a thought:

If the solution (or water) get's too warm like let's say 90/F then the oxygen available to root
drops off and when your working in a green house or hoop barn heat can build up fast. I had this happen to me and could not figure out why the roots were brown and cruddy when I was giving them such a good soultion. Then I found problem was that the ambient air around the system was heating up containers and pipes so by the time the water arrived with the pump the water was way too warm to be absorbed and the plant could not drink it , I would not want it either when
it is 90/F I would puke it up.

cold water can hold more oxygen than hot water