If you're overwatering with a 4" gap would I be right in thinking the medium holds too much water? After all the pwt is below the root zone so either the gap is too small or the medium not airy enough??
i thought i was at 4" air gap but when i had checked the water was all the way to the top so i drained the res and lowered the float valve. now im sitting at 4" i think.
gonna change my watering schedule 20 seconds every 1.5 and see how they respond. my manifolds flow heavy