Trying to determine if I like MP rotators I switched out a zone on my system from 20' brass spray to rotators. I reconfigured my WM smartline on that zone from spray (default is 1" ph) to a .5" ph setting. We can only water 2 times a week here so I like to see how many minutes have accumulated before its next watering time. They spray zones all show 10 min and 16 sec. The rotator zone shows 30 min and 50 sec. Did I miss out or have forgotten some math from my early irrigation training? It seems to me the MP zone should be at 20 min and 32 sec. All other factors are the same. Warm season turf, clay soil, 10% slope.