I am looking at a Katadyn® Vario Microfilter for  my gear what is everyone's the opinion of this filter

Honestly it depends on your requirements.  
Family camping ...GTG
Everyday "just in case" filter....GTG

But if space is a factor...ie, in your BOB, there are better options IMO...like the Sawyer one

Gear for what?  The Vario does have a carbon element that will help filter out pesticides and most heavy metals; good for being around a lot of agricultural farm land and/or most suburban water points.  

For most SHTF, camping/backpacking needs, it's fine.

What it lacks is filtering out viruses (as do most backpacking filters).  While not essential for most North American recreational needs, a protracted crisis where sewers are a backed up, not pumped, areas flooded, etc., this is where viruses thrive.  While your Vario is still a filter, you'll just need to add some purification tablets (the Steri-Pen system works as well) and make sure they target viruses.  

There are some filters that also are purifiers such as the expensive MSR Guardian, well-tested First Need XL, and the newer Grayl "press" filter options that all handle viruses.  While chemical tablets/solutions and UV (Steri-Pen) will work on viruses, you will often need a filter to remove the larger particles for effective application.  Purifiers will do all of that, but if you run with just a filter, it's nice to have something handle the viruses if you're in 3d world countries, or you plan to use your filter post-SHTF around any population areas.  People poop is what often leads to viruses in water sources...common when societies break down and public services are not operating.  

Depending on the turbidity of the water sources, some means of a pre-filter will safe the lifespan and flow rate of your mechanical filter.  

Lastly, have a spare parts kit for the mechanical filters.  Also, keep a spare filter cartridge or two on hand and track your water usage; at least rough estimates.  Most of the filter with active carbon as part of their element don't last more than a couple years after exposing and using them.  

ROCK6

All this is 100% true. The only things I can add that allowing your water filter/purifier element to freeze might damage it.  If you have a Ceramic filter/purifier element, it will very likely crack if frozen, and so be useless.  Keep the 100% drained filter inside your jacket and inside your sleeping bag if freezing temps are at all possible.  Have a viable, Tested backup system if your filter goes down.

Some filters appear to have separate chambers for activated Charcoal, which can be user-replaced via Activated Charcoal from aquarium shops.  Make Certain to store Activated Charcoal in 100% sealed state, such absolutely preventing contact with atmospheric water.  IIRC, the Katadyn Combi filter has this capability: https://www.katadyn.com/downloads/katadyn/manuals/filters/manual_combi_en.pdf.  May be some others.  Their advice on replacing the Activated Charcoal is contained in the link.  It doesn't last very long.

The last thing to mention is that having a user-cleaned inlet-mounted Pre-Filter saves a lot of time and hassle when obtaining water from some ponds where surface scum is present.  Even some swatches of common nylon stockings will do, but some prefer coffee filters.  Arrange things, using a float mounted on the inlet tube ( a bit of closed-cell GI Sleeping Mat material), to allow the pre-filtered end of the intake hose to be below the surface of the water.  This reduces crud intake, and greatly extends the service life of your filter/purifier.

None of the above is contrary to what ROCK6 has written, but simply expands on his comments.  Let's ask him, and see if I'm full of it.

@ROCK6

Good point, all freezers can freeze some are rated for it (very few and they even don't recommend routine exposure like that), the majority will be damaged or severely compromised.  That's one reason I like the Sawyer Squeeze or Mini as it can go in a Ziploc and tossed in your chest pocket or sleeping bag to avoid freezing.  




This is a good point.  I like having some sort of activated charcoal filtering options, even if as a pre-filter.  This can be handy for areas that you visibly see agricultural run-off, and most definitely if an area is flooded that has any significant amount of industrial manufacturing.  For those that live in areas with hard water, sulfurous water, etc., activated charcoal does help with taste.  Once "opened", everything I've read is that it's only good for 2-6 months depending on how much it's used.  If left sealed, the shelf life is said to be indefinite.  Me personally, I would purchase a couple of the external activated charcoal filters that you can splice or add to your filtration hose if you have a pump or gravity system that they will work with.  You could still rig up a gray water bag and run water through the charcoal filter before running it through a filter like the Grayl system (it also has active charcoal, but suffers the same problem with expiration and the spare filters are pretty bulky).  The reason I like the smaller pre-filters like that (Platypus has one, MSR use to have some) is that you don't need it unless your water is skunky tasting or you enter an area that is suspect of heavy metals (flooding, ag area, etc.).  Just my personal TTP.



This is very environment-dependent.  I did some backpacking in the Cascades decades ago with a Katadyn Pocket filter.  I was filtering some pretty silty, glacial runoff and man, the silt would build up so quickly on the ceramic filter I had to break it down and scrub it off several times.  Same goes for some of the "swampy" waters of the Southeast.  I've used Sawyer filters in the very murky, highly-tannic, heavy detritus swamp waters and many of the capillary type filters clog quickly and need to be back-flushed frequently.  

While I would highly recommend a pre-filter of some type, especially if filtering on the move with poor quality water.  Another option for an evening campsite, is having a container to collect water and let it settle and then filtering off the top (I use the Sea-to-Summit folding 10L bucket, weighs less than an ounce and folds down to about a C-cell battery size).  

All good points Raf and really should be considerations before investing in any filtration system.  Your water quality, agricultural run-off or frequent flooding around built up areas, and seasonal temperature uses.  I know the initial investment sucks, but if I was to buy a new filter I would immediately pick up a spare filter (or two), packets or activated charcoal pre-filters, an easily cleaned pre-filter, and possibly a repair parts kit (especially for the pumps or those that rely on o-ring seals.

ROCK6

Our group just had a water purification class and the local expert recommended Grayl filters anyone experience with these?

I've got their original and larger GeoPress. The larger version has some better features, but I used the small one as my travel filter going back and forth to Afghanistan for almost two years.  They work as advertised.  I like that the rubber gasket is part of the filter cartridge that gets replaced vice wearing out.  The filter cartridges are good, but like most filtration systems, once used/exposed it has a limited life span. I have extras, but these filters would make a good option to keep in your kit.  

They're pretty fast to filter.  I like that I can fill other containers quickly or just as a solo, fill, press/filter, and drink on the move.  This is a purifier: removes viruses and heavy metals.  I would strongly recommend this for a single-solution, solo-water system if you're traveling abroad or planning to be in an urban area and needing to bug out after a disaster where water will likely have more contaminants than other sources (rural/farming is another source of heavy metals/pesticide run-off).

ROCK6

Sawyer filters use the same nano-tube method found in older kidney dialysis machines, but was halted due to the tech removing some of the good stuff as well.

For water in a pinch, I’m OK with that tech.

Chris

Thanks for the info.  I now have a couple on the way.