Purenex Multipure Aqua RO System - Manual (Page 18)

NOTE: Check air pressure when tank is empty
Step 1 Using a digital air gauge, check the air pressure in the tank. You
should always have between 5-7 psi. If you have more than 7 psi,
release air and recheck. If you have less than 5 psi, add air, air can
be added with a bicycle pump.
Step 2 Your unit comes with a stand for your storage tank to sit on if you
need to turn the unit on its side.
Step 3 This allows for air flow under tank keeping moisture and standing
water from rusting on the bottom of your tank which would void
your warranty.
Maintenance - Check Air Pressure in the Tank
18