Lol what!?! I think I just lost a lot of respect for them or I learned something new.
My res gets the bubbles and it's pumped to the elevated bucket. Any excess returns to the res. The bucket is gravity to the main line across the back wall. Then the tee's and valves feed each plant. I don't think I'm getting any air in the lines this way. Just trying to give the roots some oxygenated air and keep the water fresh. The drippers has slime built up on them which plugged em shut and stopped water flow. I also have some algae in the shut off valves which stopped the water to others. Don't think drip clean helps this as it's more for salt I believe.
