[instaclay]

That's what I was thinking. This makes me think my system is less safe than I thought. BUMMER!!

This poster's cost drop on the $2/5Gal made me go down the cost analysis train on my own system.

I setup my own robust RO system at home and filter my own water. It uses a 20gal tank so the output is very high when demanded (slow regen, lots of storage). We use about 1400gal of drinking water from this system a year between 5 people and 3 pets (I filter their water too), filter media needs replacing every year. (1400/5)*2 = $560/yr cost if purchased water from "Whole Foods" which I don't have access to. I also use the water in the winter for humidifier units, so that probably boosts my usage a lot.

Filter replacement costs are ~$80 per year plus the RO membrane every 5yrs (80/5) 80+16 = $96 per year on media... let's just call it $100 to add margin for o-rings replacement or other tooling or random things.

560 - 100 = $460 savings over "Whole Foods"!! Neat! Not counting the convenience costs too.

Original investment for the system: $580.

Break-even in a bit over 1 year doesn't seem bad. Its been 4 years since I started doing this, so it seems like I am well ahead already.

Input water cost is minimal, I pump ground water so there's no cost other than electricity. There are other costs to my water treatment system that I won't include in the "drinking water" category since that's whole home. I also treat for iron/arsenic, which was a 1.8k filter and costs ~$80 in reagents per year.

[taftster]

Labor cost for sourcing and replacing the filters, o-rings, etc. should be factored in. And of course, sourcing the bottles from Whole Foods in comparison.

I like your evaluation here, not criticizing it. But I'm curious about adding the costs for time/material/travel to your costs.

For me, I'm not going to run a RO system because I can beat the cost against Whole Foods. I'm doing it because I believe in the RO system (even though the article casts a bit of a knock against the plastic membrane, which is unfortunate).

[instaclay]

Oh, I have no plans of not drinking RO water because of this article. It was just interesting to me. Whole Foods water is very likely RO water too. Both my water and a grocery store water source are probably going to be very comparable as far as quality.

Sourcing the filters is extremely easy, I order them in sets of two complete sets every other year, since the cost for order two is slightly less.. then I can order them on some on-sale price instead on on-demand.

labor is extremely minimal. I have to replace filters only once per year and it takes about a half hour of time.

Labor saved over transporting water from off-site is not in the same ballpark.

I was inspired to do this because I tested our well water for arsenic and wasn't happy with the results. It was 30ppb, and it's now 2.5bbp from the tap (after the iron filter, but before the RO filter)

I had gotten the RO system in hopes that's all I needed, but after testing the water out of the RO system for arsenic, I was still unhappy with the results. ~15ppb... so likley un-oxinidated arsenic. Adding an iron filter to oxidize the water and remove both iron and arsenic did the trick.

Before I installed new filters, I started sourcing my water from grocery stores by buying 1gal jugs and it was more than tedious. I had new children in the house and I was wanting to avoid having them drink water that may be high in arsenic. With storage, travel, lugging large quantities of water around the store, and having to manage the milk jugs they came in was way more work than I wanted to do every week. It would have been easier if I had access to 5gal jugs, but still more work than the system is now. I had bought 5-10 1/gals each trip.

The store also uses an RO system, treating and filtering municipal water from tap on-demand. They don't truck the water in or store it. The regeneration, even with their large system is slow, so filling up 5-10gal jugs took a long time and there was sometimes a line. I did not like doing it. I would guess the time I would save not changing filters once per year would be eaten up by 1 or 2 trips to the store.

Pre-filled jugs were available at higher quantities for 3-5x the price.