Oxygen dissolved in the water would normally be {TAIL ~ less than 8 pm} and a manually selected ratio assuming {HEAD ~ 8 ppm} would be adequate for smaller installations 
Oxygen dissolved in the water would normally be { TAIL ~ less than 8 pm } and a manually selected ratio assuming { HEAD ~ 8 ppm } would be adequate for smaller installations
OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH