I had an experience adding a whole-trailer filter to our 2018 25FBT that I'd like to share. We are using a filter housing positioned after the water pump along the lines of #18
, but we had to do a bit of research to get a filter that worked well with it.
Our 2018 25FBT has a Shurflo 4008 Revolution pump rated at 3 GPM. We knew we wanted a 0.5 micron carbon block filter, and at first we tried a Pentek CBC-10
, but apparently the 12 psi pressure drop of this filter was too much for our pump. When a faucet was turned fully on, the pump would continuously cycle on and off instead of running continuously. When shutting off a faucet, the pump would stutter five or six times instead of stopping pretty much immediately as it should.
A bit of searching turned up another 0.5 micron filter filter, the Pentek FloPlus-10
, which has a smaller pressure drop of 2psi. With the FloPlus-10 our pump stuttering went away entirely - the pump sounds just as it did before there was any filter hooked up. The FloPlus-10 is a bit more expensive than the CBC-10 but is still very economical. I'm very happy to have found it.
One other thing - While the Shurflo 4008 is rated at 3 GPM, the FloPlus-10 specifications are stated for a flow of 1 GPM. I understand if the flow is too large through any of these filters, their performance can be compromised. We measured a maximum of 1.3 GPM at our galley faucet, so the pump, plumbing, and filter seem pretty well matched.