I got my DE filter and heater replaced today. I asked them to install two jandy 2 way valves so that i can bypass the heater if i want to. Please see the pictures below and tell me if they have done it correct. The installers barely spoke english so they were not able to explain to me. Also do we need to add DE before starting up the new pentair FNS DE filter ? They did not do that and ran it for 4 hrs, now the pressure meter shows 32. Its a Pentair 460737 mastertemp 400k btu, is propane gas model and Pentair 180008 fns plus filter 48 sqft