Water Filter Advise

Hi Gil,

I’ll comment on some of your thoughts in an attempt to help as you work your way through this.

myredracer wrote:
I had no idea what the effect of a carbon block filter can be from chlorine reduction on the downstream water. I am going to go back to the drawing board on the "whole house" filter I bought, a Pentek Floplus-10. I chose it because it's 0.5 microns, is designed for a high flow rate and it combines carbon, sediment and micro-organism filtering all in one. While it does have a polypropylene media, it does not have KDF or silver in it. I just looked at the fine print that I didn't see before and it says "Warning: For drinking water applications, do not use with water that is microbiologically unsafe or of unknown quality without adequate disinfection before or after the system." It sounds like if you are not using water from a treated municipal system and the water quality is unknown, this filter is not a good choice.

I found this cut sheet on the Pentek Floplus-10. Strange I could not readily find it on the Pentair Water web site, but found their tech sheet on a retailers web site http://www.allfilters.com/files/pentek-floplus.pdf

If you are going to use this as an entire camper filter, you may find if you put a sediment filter upstream from it may help. It all depends on the water source, however a 50, 20 or 10 micron may help as a pre-filter to help slow down clogging of the main filter. I suspect you will find going with a straight 0.5 micron filter as the primary unit may give very slow flow after a short while. While the pressure drop may be better than a comparable 0.5 micron unit you may experience ~ 30 minutes to fill the fresh tank. If you are hooked to city water, then it may not be “as” noticeable. Many RV faucets have small restrictors in them to about 3 gpm at full flow. According to the Flotech-10 chart, with a new filter, there is 2 psi/1 gpm. Or 6 psi loss when the main sink or shower is running wide open on a new clean filer. That pressure drop will increase as the unit becomes more clogged.

Their warning sticker I’m assuming comes for a general caution to only use this filter on known potable water and that has something chlorinated downstream. If a high bio load comes into the unit that was not from a potable source, given the right conditions that may grow out of control as the carbon unit does not contain a bacteria static agent.

In a house system on chlorinated city water this is generally not a concern. However on a RV, it will reduce the chlorine downstream by a good amount and our campers can get real hot inside when stored during the summer out in the sun. So that is something to think through. If you use this filter, you would fall into the group of folks who some put them in the freezer between trips. As I said before, I have no experience in doing that and cannot comment on how effective it is.

I grew up on chlorinated city water. After being on well water for 20+ years, when we go anywhere that has chlorine in the water, it seems almost overpowering at first. We don't find it offensive enough though to make a carbon filter a must. It seems like the carbon particles aren't just there for the chlorine though.

Yes, you are correct, the carbon takes out things other than chlorine.

I still want a decent flow rate filter with a lower micron rating and with KDF or silver to prevent bacterial growth. I was looking at a 10" Pentek whole house filter that has KDF in it but it is 4.5" in dia. and retails for $80, so that's not an option. Perhaps two filters would be a good choice - a main whole house one and a separate one under the kitchen sink just for drinking water? I drink a lot of water straight out of the tap. In reading your links on KDF and Silver, it seems like KDF would be a good choice. I don't know what that does to cost or dimensions.

Yes, KDF is the newer method. When I have broken the top off of one of ceramic carbon filters I can see the KDF mixed in with the granulated carbon. It looks like the granulated KDF right off the KDF web site I linked you too. From my background, I would recommend the KDF or silver when using a carbon filter.

Yes, if you use a fine sediment filter on the incoming city water this lets the chlorine come through. The pleated filter I linked Fisherguy is a washable one. As we know, only use sources you know are potable. At the sink, then go with a fine micron carbon filter as a point of use filter to reduce out the chlorine and other things carbon tanks out. Again a filter with KDF or Silver in it and work through how to drain it and dry it out when not in use. Mount it in an easy access area. Naturally this all comes with 1 or 2 system sanitizes per year pending use of the system and good water practices.

Here is a photo of the strainer out of the water inlet fitting on the exterior of our TT. This is how it looked 2 months after winterizing at the end of the season. It looks to be about 50% or more covered in something. Interestingly, the strainer at the end of the hose at the CG faucet is perfectly clear. I always check the one at the faucet end but never thought to look at the one on the inlet. I have no idea what the material on the strainer could be. Algae? I don't exactly relish the thought of ingesting the stuff whatever it is. Could the stuff also be somewhere in the water dist. system inside our TT?

I myself have not seen rust colored algae. The types I have seen are a variety of green. Even when I find a bio mass in our machines that goo is more milky colored. And our bacteria “goo”, may be from the types of bacteria we have feeding on the proteins and fats in the products we make.

That said, were you camping in an area that was high in iron? This is total speculation but there may be “something” stuck to the screen and then a high iron source came through and attached to the stuck something. Does it smell like iron or foul something? This one I do not know. I would for sure do a good sanitize of the camper come spring when you start using it again.

Related to this thread, I came across the below article recently on Legionnaires disease in RVs. When I looked into to it, it seemed highly improbable that this would be a concern in RV systems because it normally occurs in highly complex water systems such as in large buildings; in systems with lime scale, sludge & rust buildup; and in holding tanks where there are elevated temps (68F and higher) for long periods. And then you need to inhale the infected water, not drink it. Not really conditions present in an RV.

The article cites a case of an RV-er that contracted the disease but was already in a higher risk category to start with and it doesn't include any evidence on exactly how and where he might have contracted it. If it was a problem in RVs, I have to think you'd hear a lot more about it. In reading through the article, it doesn't seem particularly credible the way it was written.

Legionnaires disease in RVs

Thanks for the link. Interesting to read. I am not really up on that disease, however the study did site this in their investigation.

3.2.2. Demographics

All of the RVs in the study were registered in southern states including: TX, GA, FL, SC, VA, and NC except for one registered in the state of OH. The four RVs culture-positive for Legionellae were registered in different states, GA, SC, TX, and TN (Table 1). The average model year of all the RVs included in the study was 1997 and the average model year of all of the four positive RVs was also 1997. No specific make or model was associated with a positive Legionella culture.
3.2.3. Maintenance

Fifty percent of all the RVs surveyed had RV general maintenance performed within the last year with 60% of RVs having the water tank cleaned within the last year. Only one reported cleaning the water tank with chlorine. Others reported draining and or flushing as the cleaning procedure.

Forty-five percent of all the RVs would have the water tank drained when the RV was put in storage. However, only one of the RV owners treated the RV tank with chlorine before putting the water tank back into use.

A few points that stick out, southern US states, = hotter temps. When the temps are hotter, many bacteria thrive a lot better. Older campers, while they themselves are not a problem, regular chlorine shock sanitization was not done. This does not matter new or old, however if years have gone by with no sanitization, odds are not in ones favor in a real hot climate for not having an out of control situation.

You mentioned you had to inhale the water, this may be possible. This stuck out.

2. Case Report

A 50-year-old previously healthy man who smoked occasionally and drank moderately attended an antique car exhibition in rural Pennsylvania in the fall of 1993 with several other enthusiast friends. The group traveled by RV and lived in the vehicle for several days using water for drinking and bathing directly from the storage tank. The water supply was replenished when required by refilling the tank with local tap water from a municipal system.

If someone is showering in their camper with heavily infected water, odds are present you could inhale steam vapor or even mist while showering. This might be a path for an inhaled infection. And while they used chlorinated water to fill the tank, if the bioload in the system is high, there is not enough chlorine in potable water to knock it out. The free chlorine that is present gets consumed trying to burn off the infection until can’t any longer as it is all used up. If it never knocks out the source, it just keeps leaching out nonstop into the water in high temperature conditions.

Hope this helps

John