Saturday, December 9, 2023


What type under-sink water filter do you recommend?

Dear Dave,
I’m thinking of putting in an under-the-sink water filter. I am wondering when I winterize my RV, what do I do about the filter? Do you have any recommendations on what type or brand? We are part-timer RVers that go out a week or two at a time. —Chuck, 2019 Grand Design RSL303

Dear Chuck,
If you are just wanting to filter the water going to the faucet in the sink, you can use a smaller residential version found at home improvement stores or on Amazon here.

You can get a single stage or three stage, depending on the level of filtration you require. Many RVers will put an inline filter at the faucet outside to filter all the water coming in for sediment, lime, and rust. You can get the in-line version that is easy to assemble. Or I like to use the residential style as I can replace the cartridge for about $4 rather than the entire filter, as campgrounds in my area have very hard water and plug a filter pretty quickly.

Another option is to get a portable water softener that not only softens but filters as well.

And the ultimate is a Clear Source system that filters almost everything!

I like to use the Omni Filter I can get at home improvement stores.

Test the water

What you might want to do is test the water to find out what type of minerals and level of hardness it is. All home improvement stores have kits that will show hardness, nitrates, ph, copper and several other items.

If you go with the under-the-sink brand, as you indicated, take out the filter and let it air dry at home. Some filters come with a bypass plug you can insert where the canister was. This is good if you are using RV antifreeze, as I wouldn’t want to fill the canister with the pink stuff. You definitely do not want to get the pink stuff in the filter. If you are using air to blow out the system, I would still take the filter out and let it air dry as freezing would most likely weaken or destroy the inner filter.

Filter for drinking water

One last recommendation. If you are looking to just filter water for drinking, I used to go and buy 5 gallons of water from a grocery store that has a Culligan filtering system. However, it was quite a pain hauling that heavy jug back out and into the camper or at home. I use filtered water at home as I don’t like the taste of soft water. Even with an under-sink filter we were getting scale in the coffee maker. I started using the Brita filter and it works wonderfully. Here is the model I have. I take it camping with me, as well.


 You might also enjoy this from Dave 

What filtration system do you recommend to fill freshwater tank when boondocking?

Dave Solberg is a leading expert in the RV industry and the author of the “RV Handbook.”

Read more from Dave here


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Dave Solberg
Dave Solberg
Dave Solberg is a leading expert in the RV industry and author of the “RV Handbook” as well as the Managing Editor of the RV Repair Club. He has been in the RV Industry since 1983 and conducts over 15 seminars at RV shows throughout the country.



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Lil John (@guest_216338)
11 months ago

Dave. I’m surprised you never mentioned an under the sink filter you can buy. I’m on a well and want my drinking water to be pure, so I’ve used an under the sink filter for over 30 years. No problems. When you pick out a filter, if you get the green colored ends, you cover everything. I hate carrying drinking water, and the green ended filters take out everything from lead to taste to even gerardia, which is really bad for you. By using a decent filter on your fill line, the shower and sinks are fine.

Last edited 11 months ago by Lil John
Leonard (@guest_216326)
11 months ago

We use a 1 micron inline filter for all water coming into the RV and a counter top Brita for drinking. Works well and we don’t need to contaminate the oceans and landfills with bottled water! Every little bit by EVERYONE helps!

Kasey (@guest_216312)
11 months ago

3M Filtrete is what we use. We have it mounted behind the false wall panel under our sink, which makes changing it out a little more involved, but it keeps everything neat and out of the way…and our under sink area gets cleaned and organized at least 2-3 times a year when we swap 😉 We’ve been using it for probably close to 10 years with no issues. Easy to find refills and easy twist on and off. They make a bypass plug that makes winterizing really easy (part number 6217401, to save someone time searching). We also filter our incoming water with an inline filter from the spigot, so the cold side of the kitchen sink is double filtered and good enough for us!

Bob p (@guest_216291)
11 months ago

I wouldn’t go to the trouble of testing the water for contaminates for a RV unless you go to the same place every time. We carry gallon water jugs and simply go to the nearest Walmart or grocery store where we can fill our jugs for $.27-$.35 per gal. We use about a gallon every day and a half for drinking, and don’t worry about the other uses.

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