RV Water Filtration
We’ve used several single canister water filters on our RV in the past, but our water lines still managed to gather particles that would slow or stop the water flow to our faucets. The problem was especially noticeable in the kitchen sink and the shower. Restoring full water flow required finding where the particles were lodged in the lines, and then cleaning them out. This usually meant removing cabinet doors in attempt to squeeze into the small spaces under the sinks. We found a solution: build our own multi-stage RV water filtration system.
After doing some research, I found that most of the single canister filters are made with carbon filters. These filters are really only good for the taste and smell of the water, but do nothing to keep the water lines clear of sand, silt, scale, and rust particles. After doing some research, we built a three canister system with high flow canisters. We choose to use high flow, rather than standard size filters, as we didn’t want to decrease the water pressure. The high flow filters have an initial pressure drop of less than 1 pound per square inch (psi). We connected them in a line with the first canister having a 5-micron nominal filter, the second with a 1-micron nominal filter, and the last with a carbon filter. At the end of this article I’ve included a list of all products we used to make this system.
If you’d like to purchase a 2-stage filtration system, rather than build it yourself, we recommend this one from Clear2O.
Filter Types
It turns out that water filtration is fairly complex and there are many types of filters. There are a couple of terms that made choosing a filter system easier. First, a micron is one millionth of a meter. That is very small. While many particles that you would need to worry about in the water are greater than 5 microns in size, the average length of bacteria is about 1 micron.
The other terms are related to filter construction. An absolute filter is designed to capture 99% of the particles of the size of the filter, whereas a nominal filter will only capture between 60% and 98% of the particles. So, a 5-micron filter that is nominal will not capture as many particles as a 5-micron absolute filter. However, by using a series of filters, you should capture most of the particles even when using nominal filters. To remain effective, change the filters every 4-6 months, according to the manufacturer and the amount of particulate in the local water.
Danger of Inadequate RV Water Filtration
The danger of not appropriately filtering the water for particles before it enters the RV is that it can damage the appliances. The water heater, in particular, can suffer from having a lot of particle build-up. Also, the water flow in the RV will gradually decrease to a trickle, which we learned the hard way.
Off the Ground Storage Rack
In addition to the filtration system, we built a PVC rack to hold it off the ground since don’t have room in our water bay to mount the filters. You can build a stand for less than $20 using PVC pieces from Home Depot. It was built for easily disassembly for storage while traveling. The set-up takes less than 5 minutes to assemble, including hooking-up the hoses when arriving at a campsite.
Cost to Build a Multi-Stage RV Water Filtration System
Grand total for the filters minus the PVC stand (which was only ~$20 to make) was $130.06. I already had the Teflon tape, which might add $2 to the total.
Product List
From Amazon:
(3) Pentek 150237 #10 Big Blue Filter Housing, 1″ Female NPT Inlet/Outlet $26.78 each
(1) Pentek DGD-5005 Spun Polypropylene Filter Cartridge, 10″ x 4-1/2″ $12.49 each
(1) Pentek DGD-2501 Spun Polypropylene Filter Cartridge, 10″ x 4-1/2″ $10.63 each
(1) Big Blue Coconut Shell Carbon Block Water Filter Cartridge 10″ x 4.5″ $15.99 each
We also purchased a new water hose that is collapsible for easier storage and an adjustable water pressure regulator:
Zero-G Marine/RV Drinking Water Hose $33.95
Water Pressure Regulator $42.99
From Home Depot:
(1) ¾” x 2” GAL Nipple $1.97 each
(2) 1”x3/4” PVC Bushing $1.38 each
(2) 1”x3” GAL Nipple $2.94 each
UPDATE (September 23, 2017):
We just changed the filters for the first time since installing this system. They are shown here from right to left (from the water source): 5 micron, 1 micron, and carbon. As you can see, they are certainly doing their job!
Feedback Welcome
Please feel free to leave comments or suggestions. We are water filtration newbies and would appreciate any feedback or ideas for improvement.
For another preventive maintenance task, see how to easily flush your water heater.
For complete information on your RV’s water systems see:
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Wow. This is interesting. We have some sort of “whole house filter” that is built into the RV and has to be replaced every couple of months, and in certain places, we’ll use an additional filter at the spigot, but I think they are both the carbon filters you’re talking about. Lord knows what damage is being done to our appliances. At our old house, we had all kinds of problems with our hot water heater because of the minerals in the water. I imagine it’s probably going to be a whole lot worse with the RV. We’ll have to read more on this stuff. Thanks for the post!
Our next video is a clean out of our hot water heater now that we have the three-filter system in place. It will be our baseline to compare to future clean outs.
Hi there,
Excellent article!
The only thing I would comment on, is the use of galvanized nipples and couplings. Go the plastic route and you may actually get a longer life out of the smallest filter. The galvy that is used on the metal nipples has two problems; one, it’s not very good (it flakes off inside the pipes) and two, the galvanizing has heavy metals like cadmium in it, so when it comes off (especially on the fitting after the final filter) it can go into the water you are using.
Just a thought, from a retired pipefitter and old merchant marine engine room guy.
Thanks for giving me a great idea for my winter project when I get back!
Thanks for the info. I will have to start changing to plastic.
Ok so I have done this same set up but when I turned on my water every one of the canisters were leaking. Why is that? But I do not have the water pressure regulator because I was told I shouldn’t need it.
Hi Justin. It depends. If it is leaking from the canister, it may just not be sealed. Check the rubber gasket in the canister. Also, we have noticed that our canisters drip a little the first couple of minutes when we turn them on after moving campgrounds. They stop leaking after a few minutes.
If it is the connections between the canisters, get some plumbers putty to use to seal and gaps in the threads. That will take care of it.
You don’t need a pressure monitor for the filters, but you should have one to monitor the pressure going in to the RV. Most manufacturers recommend 60 PSI or less. We keep our between 45 & 50.
If the solutions above don’t work, let us know and we will troubleshoot with you.
Pasang Filter Air Bandung Hi Justin. It depends. If it is leaking from the canister, it may just not be sealed. Check the rubber gasket in the canister. Also, we have noticed that our canisters drip a little the first couple of minutes when we turn them on after moving campgrounds.
Great idea!! I see the 5 and 1 micron filters are spun polypropylene for resistance to chemicals and bacteria but don’t see that for the carbon filter. Since we are weekend campers, for now, would I have to replace the carbon filter every weekend?
I wouldn’t think so if you drain the water out of the filter housing when you complete each weekend trip.
I would advise adding a water softener to your water filtration system. It will decrease the calcium carbonate in the water. You will have less mineral buildup in your water heater and fixtures. Plus, soap rinses better from your hair and clothes.
Thanks for the tip! We’ll definitely look into that.
Why did you choose to go with the 10″ filter housings vs the 4.5″ x 20 long?
Hi David – I read that were were better for flow rate. It turns out that our water flow was not positively or negatively affected by the housing we chose. I don’t think it makes a difference either way.
This is awesome. I’d love to make something like this one of these days!
We’ve used it all kinds of conditions for over a year and it is still doing a great job!
We actually met someone that sells these already made for over $400. So glad we were able to DIY it for a little over $100.
Hey I just finished this build. Have to say, I really appreciated the video and links to amazon. I started with just the 5 micron and carbon, as it is better than the standard camco we were using. I just ordered the 1 micron. Overall, pressure is great.
We were at a campground and the water would come out hazy with the camco. Once I had the 2 filters in place, it came out clear! Huge improvement. We are full timers and I am looking forward to clean water! Haha
Questions and comments:
Did you move to plastic fittings, and if so, where did you get them? (Link if possible)
Did you end up going with a water softener? I thought about buying one of the smaller ones.
When I first put the housing together, it leaked bad. I realized quick they have to be pretty tight. Once tight, no issue.
Overall, thank you!
Thanks for the feedback, Mike! I did not move to plastic fittings. We do not have a water softener yet, but I am seriously considering it. I think it would bump up the quality of the water even more. I would like to figure out how to make one DIY. After moving a couple of times, our leaked at the connections. I bought some stuff plumbers call “pipe dope” and put it on the threads. I have not had an issue since. I am still really happy with the system…especially after seeing a similar set-up online for over $500.
This is an amazing DIY project! I love having such filtration system on my RV too. We have been using our RV for vacation and we always need some good source of water to use.
We are currently putting this together so far easy! My question is have you used in the winter? We live full time in Indiana and looks like this winter is going to be rough. Our underneath is enclosed and insulated but not heated. We haven’t had any trouble with pipes freezing. Any suggestions would be great. We have an older remodeled fifth wheel.
We’ve only used it when the temperatures were low 20’s for a few days. Definitely keeping it under the insulation will help, but I’m not sure if it will be enough in Indiana. I’d think if your pipes are freezing, then this won’t either.