Here's my standard cut-and-paste regarding water filters...
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Everyone has their own "system" of filtering water... Tap water quality will vary from park to park, and region to region. Your needs will depend on the local water quality, and each persons personal feelings on what is "good' water or how it tastes.
The blue cylindrical water filters from Camping World (and others) are expensive for what you get. I was fortunate that I could pick up a pair of 10 inch canister filters from a industrial system that was decommissioned / dismantled in the 1990s.
See https: // http://www.amazon.com/Pentek-PENTEK-.../dp/B013GV4ATQ
Mine have clear housings and no red pushbutton pressure relief valve... They were in use in the plant for at least 5 years, then lived on my old s&b house for over 20 years, now on the RV. Should you chose to buy those you will want to get the special wrench (under $6) to open the canister and a spare O-ring or two - it will crack, stretch or break with zero notice and you will not be able to get a seal until you replace it.
Note that These industrial filter housings have common pipe threads on the input and output ports... They come in 1/4 inch, 3/8, 1/2 and 3/4 inch threads and the smaller you go the less flow you get. Some models have the threads cut into the plastic body, some have brass threaded inserts. Mine have 3/4 inch bodies and came with 1/2 inch brass fittings screwed into the bodies. When you install them you want the input water to feed the port that feeds teh canister (i.e. outside-the-cartridge) so that you can see the sediment buildup on the cartridge (through the clear jug).
I specifically selected the housings without the red button pressure relief valves as I've had those pushbutton valves leak... they started to drip after a few years of monthly filter changes at a prior industrial job. I just close the upstream valve to shut off the water, then open a downstream valve to release the pressure. Im my case the first housing has a 5 micron sediment filter, the second has a carbon block. I go through 3 or 4 sediment filters for every carbon block filter.... your mileage may vary with the local water.
Another point... pressure regulators:
RV campground water pressure can be all over the place... I suggest that you acquire a good pressure regulator. I have read comment threads here that mention extremely high water pressure - and some have had their RV systems get overpressured and damaged (burst pipes, floods, etc). There are two types, one is just a flow restriction, the other is a true pressure regulator. Both types are available in brass or plastic, I prefer brass. Both are made with pipe threads (mounts inside the RV, requires a high pressure fresh water hose) or hose threads (can be screwed to the hose bib and can be left behind or stolen, the hose goes after the regulator and can therefore be a lower pressure rated hose)
This is a true regulator and has hose threads: https://www.amazon.com/Renator-M11-0.../dp/B01N7JZTYX
The flow of my system is this: the campground hose bib feeds my input hose, which connects to the MH. There it feeds a brass pressure regulator (with the built-in pressure gauge) then a ball valve shutoff then the two filter housings then a convenience hose bib and a short hose to the original coach plumbing.
If I were to ever replumb my MH I would mount the dual filter canisters inside a new door in the side the RV (the back side of kitchen sink cabinet is presently wasted space), and have the center tap between the two filters feed the toilet supply line, the shower, and the washer/dryer (if I had one). After all, carbon block filters are expensive, why waste one on the non-drinking water?
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