This passes {HEAD ~ treated water} from the chlorinator chamber in the reverse direction through the 5 micron filter and back to {TAIL ~ the chlorinator chamber} 
back to
This passes { HEAD ~ treated water } from the chlorinator chamber in the reverse direction through the 5 micron filter and back to { TAIL ~ the chlorinator chamber }
OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL