UV filtration for catchment water

[Kalena]

Any recommendations for filtering catchment water to make it drinkable?

[Mangosteen]

This is what I use on the water pumped into the house and then I filter it again with a pitcher type filter like Brita.

https://international.sawyer.com/product...ck-wash-2/

https://www.brita.com/

[Seeb]

They have UV set ups at the catchment place across from Ken’s

[Hunt Stoddard]

As stated above, they're available at Water Works in Hilo. They might also be available at Ferguson's, I don't know. I'm sure they're also available online. They're a little pricey, and you need to change the UV bulb yearly, and of course you need to install or have them installed and power them from 120V. They actually "purify", not "filter" water, so they don't take out particulate matter, but kill whatever's there with ultraviolet radiation.
Alternatives include electronic distillation for small amounts of drinking water or reverse osmosis filtration. Or, you can only bath in catchment water and get your drinking water at county water stations. Then you'll also have to use county water to wash veggies, brush teeth, etc. or else you kind of defeat the purpose.

[Hunt Stoddard]

Not that I recommend this solution: but I always thought it would be kind of cool to have a dual water system; so you would actually plumb your bathroom and kitchen sinks separately from the rest of the house. The sinks would source water from hauled county water, have a separate little tank, pump, pressure tank, etc. You could probably get away without even a pressure tank if you used small amounts and didn't mind the pump always going on.
More than likely this would be more of a hassle than just going UV for the whole system, but it's an idea.

[Kenney]

We got ours at Island Catchment. Definitely pricy. (Close to1 k) I heard there's another place in the new Kea'au Industrial Area where the same system was 200$ cheaper. We want to find that place before we spend 75$ on new filters.

I feel confident that our new system is germ free but it tastes yuck. We still haul water for drinking.

[MarkP]

Mangosteen!

Finally another user of the Sawyer PointOne filters. All my domestic water goes through one and I used to drink it that way. I got concerned about lead from my salvaged roofing and put in an under-counter RO system. So I bathe and brush teeth with the PointOne filtered water and drink the PointOne/RO filtered water.

Sometimes I wonder whether I have just fallen for a sales pitch since I see so few references from everyday users. I know that in the heat of the summer the water in my big catchment tank can get green. If I go too long between back-flushes the pressure drop goes up and when I do back-flush the initial flushate (is that a word? Dunno) is green whereas the filtrate is clear, just less of it, so the filter is doing something.

I bought a $10 lead testing kit from Home Depot and sent a sample from the kitchen tap and a check for $40 off to someplace in Florida. Came back with no lead detected.

Besides drinking and cooking with the RO filtered water I use it in my batteries. Very nice to have an unlimited supply of near-distilled water available for such uses. Be careful though. The new RO filter kits tend to come with a final polishing filter THAT PUTS SOME MINERALS BACK IN for taste.

[leilanidude]

What kind of flow rate (GPM) are you seeing as normal for the Sawyer PointOne filter?

[MarkP]

The SP201 is the whole-house size. They make smaller filters for backpackers.

When brand new I was able to take showers by pumping straight through the filter although at a huge 35 psi pressure drop. Any fouling reduces flow rate to the point where the tankless water heater delivers scorching hot water then goes cold when it cuts out due to low flow. That was with a standard shower head of about 2 gpm. I redid my system so that the water from the 10,000 gallon corrugated steel tank flows by gravity slowly through the Sawyer filter into a sealed tote then gets pumped from there. Flow rate through the filter varies with head which is usually between zero and 2 feet which keeps up with my 50 gal/day use easily. If I use more the level in the post-filter tank goes down further, the difference in head across the filter increases, and the flow rate goes up. The advertised flow rate is about 20 gal/hr at about 5' head. My measurements confirm this. Most households would do fine with this.

I'm really proud of my system and must have described it 2 or 3 time so far. Sorry if I go on about it too much.

My floating water intake in the big tank is a major part of the whole scheme.

[leilanidude]

I was interested in the whole house size- but that pressure drop is terrible. My catchment tank is below house grade (downhill). I do have a pair of large pressure tanks though.