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Bit The Bullet - Katadyn Gravidyn Water Filter

Discussion in 'Survival/Preparedness Forum' started by wjv, Apr 1, 2008.

  1. wjv


    Jan 17, 2002
    Pacific NW
    I already have:
    1 PUR Scout camping filter with multiple spare filters
    1 MSR miniworks camping filter with multiple spare filters

    The PUR & MSR filters both have four level of purification An intake hose filter; A 0.2 micron filter; a carbon filter; and a iodine matrix to kill viruses. If I remember correctly I once calculated that I have enough replacement PUR and MSR filters, and spare parts to purify about 8,000 gallons. .

    But that would be a LOT of pumping. . . .

    I also started stocking those 7 gallon blue Aqua-cubes from Walmart. I had planned on getting 21 of them (3 weeks worth of water), but they ain't cheap! With tax their about $10 each. So after getting ten of them I decided that I'd be better off with a good gravity water filter.

    Went to They had them listed for $169.95. Added in the 15% discount code of MAXIMUS, opted for the free (but slower) shipping, and my total was $144.45. . . Or about the price of 15 blue water cubes. . .

    So now I have 5 gallons of bleach; 70 gallons of water in blue cubes; 40 gallons in the HW tank; 40 gallons in the camper (most of the year); 8,000 gallons via hand pump camping Purifiers (will kill viruses); and 20,000-39,000 gallons via the Gravidyn. So I finally feel like I have a reasonable handle on the water situation. . Thankfully I have two sources of water within 150 yard of the house. A running stream part of the year, and a large duck pond full year round. I still plan to add bleach to the water after running it through the Katadyn Gravidyn, just to make sure.

    In a month or two I'll go back to Moosejaw and order 3 more candles for the Katadyn.


    I still want to buy a CZ rifle. . :crying: But I needed a better water filter more than I needed another rifle.
  2. Garlic

    Garlic Farmsteader

    Nov 19, 2006
    Smart man.:thumbsup:

  3. TacticalRecon


    Oct 11, 2007
    +2 :wavey:
  4. ToyotaMan


    Jun 6, 2000
    A gravity filter is really cheap for what you get and it is an essential piece of equipment to have. Make sure you use it now to make sure everything works properly, and get some spare filters for it.

    Get some 55 gallon barrels and put one under your gutters downspouts. Get enough of them and have them stored away in a shed or something so that you can replenish your stored water supply with the rain in case you couldn't run your well, or city water stopped working.

    Or in case your nearest stream or lake or pond got contaminated with something.
  5. LongGun1

    LongGun1 StraightShooter

    Good Move on getting the Katadyn! :thumbsup:

    If I were you....I would also consider getting 3 spare Ceradyn elements..

    (due to their longevity)

    .. for a worst case SHTF.

    BTW....I would not add chlorine post filtration....yuk! :puking:

  6. HouGlock


    Apr 9, 2002
    LG1, in another post you talked about using the ceradyn with a charcoal filter after the ceradyn to get the best of both worlds.

    Do you have any additional info or links on how this could be done?
  7. LongGun1

    LongGun1 StraightShooter

    To refill the Carbon filter...

    You can either buy these Katadyn
    Carbon Cartridge Replacement Packs<br>-Carbon-Cartridge-Repl-Pack/

    ..or buy it in bulk

    .or make activated carbon
  8. wjv


    Jan 17, 2002
    Pacific NW
    AquaRain makes a similar filter (with carbon) and makes the following statement: "Element life, per single element: ceramic, about 2,500 - 10,000 gallons; carbon, about 3,000 - 5,000 gallons. If the carbon wears out before the ceramic, replace the elements if you need carbon; or, if you don't need carbon, keep using them as long as the ceramic is good."

    Don't see why the Gravidyn wouldn't work the same. I think it is basically the same filter as the Ceradyn, except with a carbon core. So when the carbon is DOA, your left with a Ceradyn system.

    Am I wrong in this assumption? It there a problem that the once depleted, the carbon could become contaminated and make things worse?

    My only concern about adding bleach pre-filtering is that it would add an extra strain on the carbon.

    I do have a couple of these: lying around in my camper. They are suppose to be good for ~2,000 gallons. I was thinking of jury rigging them as a post filter / post bleach process. Walmart also sells them in their RV section.

    I also need to order a couple hole plugs so I can run the filter on 1, 2 or 3 filter sticks. With a family of 4, I could (in theory) just use one candle filter at a time for a ~8 gallon per day production rate.
  9. HouGlock


    Apr 9, 2002
    Thanks buddy! As always, great info, I love finding ways to extend the usefullness of my preps and the usefullness of my $$$!

    There's always something new to learn here
  10. LongGun1

    LongGun1 StraightShooter

    Read this page...

    ..and this one..

    ..and this...

    For longevity, health & cost concerns..

    I would recommend a carbon filter unit seperate from the ceramic unit


    ..having a carbon media that is replaceable.

    If you decide on a "Ceramic/Carbon Combination unit"..

    ..I would recommend a unit like the Katadyn Combi

    ..that have replaceable activated carbon media.

    That way you get the full life span of the expensive Ceramic.. you can replace the inexpensive activated carbon media when needed..

    ..without being forced to dispose of both. :)

    Also....when the output from a ceramic element is reduced due to the pores getting..a simple cleaning will do..

    ..vs having to dispose of a combination element that gets clogged due to bacteriological grow-thru.

    Also the clock starts ticking on the life of a carbon filter after first usage..

    ..even if you don't use it for months afterward. :sad:

    Those are some of the reasons I gravitate to the Katadyn Ceradyn "ceramic only" filter elements..

    ..instead of the Katadyn Gravidyn or Berkey Super Sterasyl "combo filter" elements.

    (Just because an combi element has silver impregnation to inhibit bacteriological grow-thru...

    ..does not mean it is 100% successful!

    No need chancing a serious "health issue"...especially during a SHTF!) filtration, you might consider UV lighting instead of Chlorine..

    I have a large stock of UV LEDs put back for this purpose.

    BTW...I was a Katadyn Dealer at one time..

    ..& still prefer their filters for many reasons.

    And though I invest a sizable amount of money in preps..

    ..I try to get the "Best Bang for the Buck" (ROI).
  11. HouGlock


    Apr 9, 2002
    LG1, this is great info. If I could indulge you for a couple questions?

    If I run water through a Katadyn Ceradyn, I was planning to run it through the AC afterwards, but the article you referenced recommended ultraviolet as well as a particle filter after the AC. Would it be best then to run water through the AC first, or to run water through the Ceradyn a second time?

    Also, how do you set up the ultaviolet to work? Trying to understand how exactly to expose the water to the ultraviolet light.

    I really like the reference talking about dechlorination as that is what I will be needing to do.
  12. kirgi08

    kirgi08 Watcher. Silver Member

    Jun 4, 2007
    Acme proving grounds.
    I just saw this and thought it might be useful down the line STS.A Katadyn MK6 Desalinator for $799.I don't need/want one,but I'm sure that there are some coastal folks that will.I read/saw this in SMGs montly flier.'08.
  13. wjv


    Jan 17, 2002
    Pacific NW
    Thanks LG1! Great info. Looks like my next set will be 3 of the Ceradyn filters. I'll also pick up a couple liters of the AC that you referenced earlier. It's pretty neat that with these types of filters you can switch out the elements to configure the system either way.

    I think I'm going to set up the filter in my house and just use every day, and keep a Ceradyn set for the long term emergency situation.
  14. mitchshrader

    mitchshrader Deceased

    Jun 14, 2005
    Thanks for getting the good info in a lump, LG1, for *at least* the 2nd time.

    I got serious Katadyn envy right now. I coulda done that, and bought .22's instead, and don't feel smart for it.

    Hope when I DO get to it, I get that good a deal. Cheapest I've heard of, anytime lately.

    Main thing has kept me from buying one I never saw a deal that tingled my cheapskate button..
  15. LongGun1

    LongGun1 StraightShooter

    Actually...the way .22 LR has been going up lately.. might have come out ahead doing it your way! :)

    Hey...does prepping nowadays..

    ..ever feel like one of those disaster Dante's Peak..

    ..where you are just one step ahead of the s**t storm? :rofl:
  16. LongGun1

    LongGun1 StraightShooter

    How you stage your filtration is dependent on your needs.

    One a Pre-filter 1st (if needed for heavy particulate matter)

    ..then Carbon element..

    ..then Ceramic..

    In my case....I plan to have the UV LED in a cistern..

    .. where the water is circulated from near the bottom..

    ..& is fed into the top to aerate the water..

    The UV is to address any bacteria, virus and cysts that may be in the water.

    The long lived UV LEDs can be parallel configed into lighting strips that can be submerged if needed.

    Also...I do not need to add chlorine if using this method!
  17. fatboy148


    Mar 8, 2007
    Congrats on your new filter! Now that you are in the Moosejaw system, you will get emails with % off codes at different times of the year. 15% seems to be the standard discount, which is good because their water filter prices are priced less than the other suppliers already. They will go 20% a few time a year also. The best one I have seen was for 25% off any one item. (The Gravidyn was like $118.00 at one point). I think that if you are going to purchase extra filters, you may be better off to get another whole filter set up, complete. Doing it this way you have all new parts including those that may fail such as the water spout. The bad thing is that it will take up more room in you storage area. The best part of doing it this way is it is usally less expensive to order the entire unit instead of just the replacement filters, go figure! If you want to play, try using the code: supersale in the check out box, most of the time it will give a 15% discount. Right now the Ceradyn has a $199.95 list price, on sale for $179.95, with the supersale discount code it is $152.95, and that is a shipped price. At this time the coupon will not work with the Gravidyn though, it is trial and error. The water filters are the only thing that I have ever purchased from this company, everything else is just too stylish for me! You will enjoy doing business with these people, here, the customer can do no wrong! Too bad more companies don't have the same philosophy. Check their prices vs those on the net, I think you will be pleasantly surprised. I hope this helps.
  18. mitchshrader

    mitchshrader Deceased

    Jun 14, 2005
    i've been surfing the avalanche since last year, LG1, and havn't felt dumb about it. one step ahead? heck, i'd like to HOPE i'm still a step ahead. more like a half step and shrinking..

    the folks who don't see it as fairly grim ain't got my perspective. i don't think the wheels have come off, but i'm real sure that thwop thwop thwop sound ain't good.

    i have no reason to think that claimed near term improvements aren't big lies. interesting times.
  19. BigFatDog


    Jul 23, 2005
    They usually are. Perception always trumps reality.

    Just make sure that while you stay ahead that you aren't raising Gazelles. I went through a selection process a few years ago. I got picked a lot of "faster" people didn't. I asked the head honcho, "why me." I'll always remember what he said, although probably not exactly the way he said it. The rose colored glasses of time...

    "They're Gazelles. When they stumble, fall and get mixed with the pack they get crushed or eaten. For tough jobs you want the guy who has been at the back and had to scratch and claw his way to the lead. It doesn't matter that he finished there. It's the fact that the knows the rough terrain and what the view looks like in the front. He'll get the job done. He wont quit. That's what matters most"

    Oh, and nice filter bcvojak
  20. wjv


    Jan 17, 2002
    Pacific NW
    Your right! It's literally a $4.33 difference!