Katadyn Pocket Water Filter Capacity — Update II

In 2016, I wrote about my estimate of my Katadyn Pocket Filter’s real life capacity.

I had reached an estimated 1,500 litres of filtered water over four winter seasons of using the filter at the cottage during the off-season when our water system is turned off. I had further guessed — hoped, really — that I might get as much as another 1,500 litres, spread over two to four more seasons, and as such it might take as long as until the year 2020 to know when the filter cartridge would need to be replaced.

I was overly hopeful. In January of 2017, I was up at the cottage for a week, doing a lot of cooking and needing a good amount of filtered water.  I tested the filter unit against the gauge supplied with the filter, and since the gauge passed over the filter unit, “it was time” to change it.

The winning total (as of January, 2017):  1650 litres. Or, about 3.3% of the oft-touted capacity of 50,000 litres.

As of September, 2017, I have not replaced the filter yet, and am at approximately 1750 litres, or about 3.5%.

This makes me wonder, yet again, what Katadyn knows about the “in the wild” capacity of its filters.  As in, how come I have only gotten 3.5% of the rated capacity of the filter before it has worn out.

And it makes me wonder why, in my perhaps modest efforts to find out how much water people actually filter with their units, just about everyone (including myself, admittedly, shortly after I bought the unit) talks about 50,000 litres, but few talk about “well I only filtered this much before I had to replace it”, or the like.

There are reviews I found on the mec.ca website there from people whose posts are meant to imply that they’ve gotten a lot of use out of their filter.  I saw one that said that over 25 years, the person was on their third replacement, and claimed to have filtered over 250,000 litres! (or over 62,500 litres per filter!)

A comment I came across said “I bought mine in 1988 and I have yet to change the filter”.  I can imagine that over 29 years one might have used it quite a number of times; but what, every weekend for groups varying from two to five people? Once or twice a year when they take their children hiking one afternoon around the cottage or campsite that they rented for a few days during the summer holidays, and the rest of the time they’re on a water system? Or “I’m an avid hiker who goes out hiking every weekend I can, and I bring my Scout Troop hiking all the time and they are constantly asking me to filter water for them”?

Yes, I have seen some reviews that are “a bit more detailed” than that, such as “well after 15 years I replaced it, having filtered thousands of litres of water” … which still begs the question: Thousands of litres of water … that sounds vaguely less than 50,000; 7,000 litres is “thousands of litres”, as are 4,500 litres, and 25,000 litres. So did you keep a log of roughly how much you filtered? Trip diaries such that you could guestimate or have a basis on which to assume that each trip you used it, you typically filtered a given amount a day and you were gone a given number of days, and at least have a ballpark idea of how much water was filtered?

And here’s one that I found mildly useful:  “I used it travelling for 18 months through India, and used it instead of buying bottled water all the time” … but that doesn’t really tell me how much water they filtered.  But, it allows for some hypothetical arithmetic.  Let’s say there were two people producing let’s say three litres per day per person for 18 months — 548 days, give or take — that’s 3,288 litres, or almost 6.6% of the rated capacity of 50,000 litres.  At four litres per person per day, that’s 4,384 litres, or almost 8.8%.  At five litres per person per day, that’s 5,480 litres, or almost 11.0%.  Now that’s a lot of drinking water, both per person, and just a lot of water to filter in a given day while travelling.  After that, I have to ask what they were using the water for!  Were they filtering enough water to wash their clothing and showering or bathing?  If so, given how much time it takes in reality to filter a few hundred litres a day with the unit, were they spending *all* of their time filtering water and not actually taking advantage of their trip in India?!?  And, of course, it should be noted that they *didn’t* mention that they bought the unit expressly for this trip, or never used it again before or after.

I am obviously getting worked up: Were I to have filtered 25,000 litres (50% capacity) or more, over a decade or two, I might not be as upset, and would likely chalk it up to the expected variation in the field due to “real world circumstances”. However, losing more than 96% of the rated capacity is frustrating to the point of unacceptable, to say the least.

The only consolation?

In January, 2017, after having passed the plastic gauge over the filter unit and having learned that it was at the end of its designed lifespan, I went to a Mountain Equipment Coop (MEC) to buy a new filter unit, not really sure whether I wanted to go through with the expensive purchase; the replacement filter units cost $235, compared to $435 for a new complete unit.

The last unit on the rack — which is the unit I therefore bought — looked like a returned unit. (Later when I got home, I was able to open it and learn that everything was there: A new filter unit, a new spigot hose, new o-rings, a new scrubby pad or two, a new bag for the spigot hose, a new tube of lubricant, and whatever else was supposed to be there.)

The list price: $235.00

The price that rang up at the till: $63.00

Discount: 73.2%

I did a double take, and without thinking I said, “That isn’t the correct price.” I of course should have kept my mouth shut, but no matter:  Québec’s consumer protection laws were on my side. Were the price at the register to be higher than the advertised price, the customer would pay the advertised price, less a $10 indemnity (with a few exceptions as well as a few other pricing rules applying as per the case); if the price at the register were to be lower than the advertised price, then the customer would pay the lower price, regardless of the difference between the two prices.

Nonetheless, we went through the motions of verifying the price on the MEC website, and indeed confirmed that the list price was $235.  However, either the clerks were savvy and well trained, knowing the law in this case, or they were naïvely trusting of the price scanner / computer / register, and insisted that the $63 price that rang up on the machine was the price to be paid.

You can be sure that the next day, I made a point of going back to the same MEC to see if they’d restocked the shelf with that item, in order to hopefully take advantage of another massive discount. Sadly, they had not. And, I expect that the store knew that the item I bought was the last unit in the store, and that (I presume that) it was a returned and restocked item, hence (presumably) the discounted price. Perhaps this doesn’t explain just how deep the discount was, but it nonetheless explains some of it. A few months later, I was at another location of the MEC and I looked at the section with water filters; they had replacement cartridges, in factory sealed boxes of course, and the price at the rack was $235, as expected. I did not dare ask for a price check. 🙂

So the experience was not a complete loss, to the point of it almost having a mildly pleasant dénouement, but the deep discount on the replacement unit still does not make up for the remaining 23.5%-ish of capacity I had expected but did not receive, and continue to not expect to receive, out of the original filter. Which, incidentally, as of September 2017, nine months later, has not yet been replaced; like one of the pub patrons in the following joke, I want to squeeze as much capacity as I can out of the filter before I finally replace it.

The promised joke:

Three people are in a pub, each ordering a drink of their preference. Unfortunately, each drink comes with a fly in the glass.

One returns the drink and requests a replacement, without a fly of course.

Another removes the fly from his drink, and proceeds to drink it.

The third grabs the fly from the drink and calls out “Spit out every last drop, you little scoundrel!”