Water filter upgrade


Having clean water is essential for life.  There are many sources for putting water into your RV and it is not always guaranteed that the water you are getting is actually clean.  As a result, many RVers will install any combination of enhanced filtration system, ultra-violet light, and reverse osmosis system which go far beyond the single filter that usually comes with most coaches.

There are many sources of information out there on how to make sure that your water is clean.  When it comes to RVs, you will find that all roads eventually lead to The RV Water Filter Store.  Rick is extremely knowledgeable when it comes to water and RVing.  Much of what I have learned came from his site and validated through other sources.  So, rather than pretend that I’m a water guru myself, I will outline the basics and the choices that I made for our water filtration.

Where to Process?

process going in...
process going in…

... or process going out
… or process going out

There are three possible positions when it comes to water processing.  You can either process the water as it enters the coach, as it leaves the coach, or both.  Each has their own merits and a fair amount of personal preference does come into play.

What type of processing method?

There are two main ways to ensure that your water is clean, filtration and purification.  Filtration is the process of removing objects from water by passing them through a barrier with openings smaller than that of the objects to be removed.  Purification, while also removes objects from the water, is more focused on overall water safety from things such as bacteria and viruses.



These are exactly what you think they are.  Systems will usually be composed of 1-4 canisters with varying levels of filtration.  First in the line will be your sediment filters.  These will remove the dirt and larger particles from the water.  These will also be the ones that you will need to clean or change most often.  Next will be the carbon filters.  These will remove odors, cysts, etc.  The large canister filters are a bit bulky.  You can place them either at the RV’s water inlet point or under the sink and filter the water at the faucet.

Ultra-Violet Lights

image courtesy of The RV Water Filter Store
image courtesy of The RV Water Filter Store

 An ultra-violet, or UV, system is a small canister with an ultra-violet light bulb where the water is exposed to the UV rays as it passes through.  UV light is capable of killing microorganisms such as bacteria, viruses, molds, algae, yeast, and oocysts like cryptosporidium and giardia.  UV won’t do anything for chlorine or metals, sediment, etc. so it’s best to include filtration along with the use of a UV system.  UV systems can handle high volumes so this one can be placed either at the RV’s water inlet point or at the faucet.

Reverse Osmosis

image courtesy of The RV Water Filter Store
image courtesy of The RV Water Filter Store

Reverse osmosis, or RO, systems are a bit complex but produce the cleanest form of water.  The system uses a semi-permeable membrane to remove a large number of contaminants.  The result is pure water.  The filtered waste is a brine that can be used to water plants or dumped down a drain.  RO systems are also the slowest to operate.  To compensate for this, they will use a collection tank to provide an “adequate” supply of water.  Putting a RO system on an RVs water inlet might seem like a good idea but it would take an extremely long time to fill an RV using RO.  This one is best left to the drinking water faucet found in most RV galleys.

What did we do?

We opted to start by filtering the water as it enters the coach.  I installed a triple canister filter at the water inlet in the wet bay.  The working premise is that we will keep our tank sanitized and thus want to ensure that clean water enters the coach.  I will use the spare water pump if I need to add water from a non-pressurized source so I can still run it through the filters.


I am running:

5 micron sediment filter (SED-5)
1 micron sediment filter (SED-1)
.5 micron carbon filter (CFB-PB10)

I also opted to make all three canisters white.  Some folks like the first sediment canister to be clear so they can the see how dirty the filter is.  Since light is what promotes bacteria growth, I opted to keep the system as closed as possible.  I can always open the canister every other month to check.

At some point in the future I will add a ultraviolet light or reverse osmosis system on the separate drinking water faucet in the galley.  This is the faucet that has the single water filter that came with the coach.  The premise here is that this would be used for drinking or cooking purposes and not  for washing or flushing.  I will most likely opt for 12v as well to keep the system as efficient as possible for boondocking.




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