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Discussion Starter · #1 ·
If it is more beneficial to leave the chlorine in the tap water, does anyone sell a 5-10 micron in-line filter without carbon? I've used one with carbon for years and been pleased, but I was just wondering if someone knows of such a thing. I've searched and come up MT.

Yes, I know I can get that with a housing, but it's less convenient.
 

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Suggest you contact the engr. at your plant whose responsibility includes wastewater, etc. OR the 'chem lab techs' ... or even your PA.
In-line 'capsule' filters are very common but bear the added cost of the integral 'housing'.

You can buy a standard industrial polypropylene filter housing, configured for 'flat gasket' cartridge sealing for 10" or 9.75'Ø length filter cartridges at Home Depot or Lowes for $60-$80

As for µM retention, especially dealing with commercial or 'coarse' industrial grade filters, beware that there is a lot of 'filter jargon' with respect to µM 'ratings'. In the 1 - 30µM range, 'cheapies' will be in the order of ≤70% retention efficiency at the 'rating', upwards to 97% reduction/retention for the 'fine' grades ... cost varies vs. retention efficiency. If you somehow need 99.99% retention, then divide the 97%µM retention by ~3. .... or consult the manufacturers BETA-RATIO curve.

Manufacturers for 'ethical' industrial usage: Pall, Filterite, GE water / Cuno, Osmonics, Parker Advanced Filtration, Meissner .... but choose their "process" division products for your selection, as you dont need 'Pharmaceutical nor Ultra-pure chemical grades' for a 'very coarse' water filter.
Polypropylene (spun-bonded / melt-blown) filter media will be the most efficacious.

Your 'filter engineering geek' at your plant should be able to get you 'evaluation samples'.
 

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Discussion Starter · #3 ·
Thanks Rich, but I'm well aware of all that, and I can get what I need for my use from the office--you know the subject well and enjoy your responses. That is a part of why I post here. However, I was looking for an answer for the common man. It seems funny that there are dozens and dozens of carbon filters on the market for boats, RVs, organic gardens, washing cars, and even pets (the dog bowl NEEDS chlorine, IMHO), but no one that I could fine offered filtration only. There are some strainers, but I think we want 5-10 microns.

By the way, filtersfast.com is a good source for much of this for the retail customer. Much cheaper and better selection that Home Depot. Penaire/Pentek private labels for many of the big guys, as does KX.
 

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You can buy a NSF 10" housing for 33 dollars and NSF 1 micron cotton filters for 6.86 each from MSC supply

It was funny a strange item came up at work that required the cotton and MSC was the ONLY place that had same day stock
 

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>>filtersfast.com
Great stuff. My only complaint has been that their automatic reminder emails can only be sent out for 12 months or less. A six-pack of filters from them lasts me longer than that. But the quality has been top, and the prices way better than other sources.

pdq-
If you want to leave chlorine in the tank...Toss in a couple of water purifying tablets? They should dilute down a long way before they get as dilute as what's in your tap water. If you have shore power or generous solar, you might plumb a UV-C lamp into the tank instead. I've got mixed feelings about chlorine. It beats dysentery "but"...
 

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Discussion Starter · #6 ·
Yup, I know about cartridge filters. I'd hate to think how many thousands of filters I've changed and the 10s of thousands projects of mine have consumed. I've also designed plants that have recycled millions.

Yes, of course we can re-chlorinate. So now I'm doing 2 things I don't want to do; taking it out so that I can put it back.

I gather the answer is the public buys carbon because they equate it with water filtration. It's the story they've been told.

The other reality is that generally hose end filters strip only 30-70% of the chlorine when operating at full flow. Not enough contact time (8 seconds empty bed) I'm betting. You would need to slow down to <1 gpm to be efficient.

Sounds like I need to do some measuring.
 

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It seems funny that there are dozens and dozens of carbon filters on the market for boats, RVs, organic gardens, washing cars, and even pets...
Nothing funny about it. Carbon filtering is the easiest, cheapest, and most effective way to take unpleasant odors and flavors out of water. That's why they are so ubiquitous. Simple economics.
 

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Discussion Starter · #8 · (Edited)
^^ Actually, it 's hysterical, because the filter doesn't do spit. I just did some testing. The problem is contact time; go to any carbon manufacture web site, look at design data and contact times for the removal of anything, and the removal generally does not become significant until some minutes have passed. unlike air filtration, it takes time for the contaminants to diffuse over to the carbon and into the pores. The process is FAR from instantaneous. As I always suspected, hose-end filters are simply inefficient depth filters, removing some portion of organics and chlorine, but not much. They will, however, stop pipe scale, some of the **** that grows in the hose, and some sulfide. Did you know, for example, that to receive NSF certification, a device need only remove 25 % of the chlorine, and none of these are certified.

I just happened to have 2 brand new filters on my desk preparing for flow testing:

Camco RV
Chlorine in 1.2 ppm
Chlorine out 1.1ppm

Shurflo
Chlorine in 1.3 ppm
Chlorine out 1.2 ppm

Given testing error, they are the same. Given they are filled with basically the same amount of the same material, they are expected to be the same.

So my tank has been receiving a chlorine residual, which helps explain why it has stayed pristine with only annual cleaning and drying. I've used a variety of hose-end filters over the last 6 years, without thinking too much about it. I think I just assumed they would adsorb little and that they would filter some, which was all I asked of them. I knew chlorine was blowing through, I just hadn't bother ed to test how much. wasn't very interested.

One less mystery, no reason to look for another filter type, since the Camco filters are only $10 complete (Walmart).

---

And now you know the rest of the story.

BTW, carbon filters in RO units and may other applications are very effective (my home RO reads zero chlorine before the membrane--I got nosy) because the flow rate is very low, perhaps 1000 times slower. The contact time is sufficient. I have one process (glycol polishing) where the optimum contact time is over 24 hours (glycol is more viscous and the contaminants high in MW). No, we don't use the RO for drinking--I trust tap water and we need the minerals--it was free and we use it for humidifiers and CPAP.
 
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