Water tablets

Keep a supply of iodine handy.

Best bang for buck will be to buy a bottle of bleach.
https://www.doh.wa.gov/Emergencies/...eWeatherandNaturalDisasters/WaterPurification

Agree on bleach but practice / learn how to do it in advance. It isnt hard but "muscle memory" fieldcraft is a premium thing to have if you can.

The answer is going to depend on your post-disaster plans, budget and skill sets.
If you're not going to be moving around, learn to construct a working sand filter that can handle the quantity of water you're going to need.
There are commercial expedition/ base camp filters that can also handle the requirements you mention, but obviously you're talking filters and other stuff that you may not have replacements for once the existing filters fail.
If you're on the move, my advice would be to buy Sawyer Squeeze filters and combine them with Cnoc Vecto's. Don't let the Sawyers freeze or they'll be useless.
Combine those with tablets or boiling if there are doubts that any little nasties got by the filters.

I think this is usually a better option. But having multiple options is always good.

https://www.amazon.com/LifeStraw-Pe...jbGlja1JlZGlyZWN0JmRvTm90TG9nQ2xpY2s9dHJ1ZQ==

Fact Sheet: How to Make Your Water Safe to Drink | FEMA.gov
Be Safe: Drink Clean Water | FEMA.gov

You should prepare to process water in several ways.

Know how to make a solar still, I always have rolls of polyethylene around. Also good for catching rain. I have two empty rain barrels, actually one is full of shotgun hulls and wads for reloading.

At any time we have 2+ gallons of liquid bleach in the house for laundry, washing, cleaning............

We have 4 Katadyne pump type hiking filters and spare cartridges. Same cartridge good for all 4.

Some water purification tablets have a shelf life.

One of these; never used this one but had another on a long canoe trip. Really nice for a stationary camp.
https://www.amazon.com/Katadyn-Base...ocphy=9005557&hvtargid=pla-415961388234&psc=1

For day hikes we use the very small purification drops and pack a couple of survival straws. Keep these in my car emergency bag too.

Iodine is good if you have a younger body. It has the potential to cause problems for people with thyroid problems, women and older people. I have a supply but for last resort. Iodine does not have a shelf life. This manufacturer is in/out of production all the time.
https://www.amazon.com/gp/product/B00N5AGT1Q/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

I do keep enough concrete blocks, bricks around for a fire pit to boil water/cook. From a garage sale I picked up a couple of big ass canning pots cheap and threw them in the garage attic. We have a whole woods behind is for fuel. (Save your propane and white gas for other uses.)

A good option is pool shock. Bleach deteriorates and can be difficult to transport. Here is an article on how to use shock. Pool Shock for Water Purification As mentioned above, having several methods is best.

I really need to make better plans for water.
Ive just always planned on being ok with our very good spring fed well water and UV system.
The water is pure and clean even without the UV and particle filters but you never know when the water may become contaminated.
Our UV system does 12 gallons per minute which is plenty of water for multiple families.

This is what we used.
Halazone USP Tablet, Water Purifications Tablet, NADCC Tablet

These, Iodine, or even chlorine bleach, it is a good idea to keep an equal supply of pre-sweetened Kool-Ade packets or the like. Helps it go down better.
Robin

@Criticalt ia that one unit with UV and particle filters? How do you like it? Ours are totally separate units.

BDinPutnam said:

@Criticalt ia that one unit with UV and particle filters? How do you like it? Ours are totally separate units.

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Its technically 3 units hanging from one bracket but is sold as a package.
Yes we like it.
Viqua UVMax IHS12-D4 UV Sterilizer w/ Integrated Pre-Filters

I have a whole closet full of these. Indefinite shelf life and according to the package, I have enough for close to a year without changing our usage habits.

Saltwater60 said:

For those of you using bleach make sure it has an epa registration number on it or it’s not approved for food use. I know if your life depends on it use what you have but you should try to buy the right stuff if that’s part of your back up plan.

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really?
all those years treating water for military and civilians....never heard that. never used that.

just start slowly and drink from ponds, creeks , mud puddles, lakes .. ect .. build up that natural immunity ..

my good friend family is on well water and run off water to the well .. rain , dirt , what ever ends up in it ,.. they buy bottle water to drink ..

i drink from the kitchen tap from the well .. .. not one issue and its been like 5 or more yrs ..

vanderblack said:

A good option is pool shock. Bleach deteriorates and can be difficult to transport. Here is an article on how to use shock. Pool Shock for Water Purification As mentioned above, having several methods is best.

Click to expand...

You beat me to it! Bleach loses its effectiveness within a year ( I think that's correct) Either the pool shock and mix it as you need it or a good filter. Be wary of Life Straws and other cheap crap, also keep the pool shock AWAY from metal! It corrodes just about everything!

Acer-m14 said:

just start slowly and drink from ponds, creeks , mud puddles, lakes .. ect .. build up that natural immunity ..

my good friend family is on well water and run off water to the well .. rain , dirt , what ever ends up in it ,.. they buy bottle water to drink ..

i drink from the kitchen tap from the well .. .. not one issue and its been like 5 or more yrs ..

Click to expand...

Third world country residents die from dysentery and other problems related to their poor water quality.
It isn't an issue of building up immunity to pathogens.

There are pathogen's and then there are PATHOGEN's. Just like Yankee's get dysentery from drinking the local un treated water in Mexico, the locals have no problem with it. A lethal pathogen would most probably be lethal to both, Though in the seventeenth and eighteenth centuries small pox was a disease that could be fatal to some western European's and Americans but to a people, American Indian's, that had no exposure and hence, no resistance to that pathogen, it was devastating. Even Measles was devastating to them.
Robin

yes and the article addresses MUCH higher PPM levels than needed for water treatment.

Pathogens are germs, some are of benefit and used to immaculate people. Well, a benefit if you believe in vaccine that is.
Robin Salk

Fire is free. Just strain it through a coffee filter to get the big stuff out. Then boil it to kill the small stuff. No need for fancy chemicals.