This is normal. DO NOT drink the first 6.5 gallons of water. Drinking from un-flushed system may cause gastrointestinal discomfort, colic and/ or diarrhea. Consult a physician if discomfort persists. Running out the first two tanks will effectively flush out the system, and make it ready for use. The tank is full when the hissing stops. Using Quick Connect Fittings To remove the tubing from the fitting – push down the seal ring to the fitting body with the thumb and forefinger while simultaneous