Easy DIY Project to Protect Your RV Water System

Last updated on October 11th, 2023 at 04:31 pm

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 an 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 chose 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 easy 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!