I recently purchased a new home and it appears to have come equipped with an Aqua-Pure Acid Water Neutralizer system, model APUN100 (not APUN100-LW as that seems to be the only thing I can find searching Google and appears to possibly be a newer version?).

The previous owner did not leave behind any literature regarding this system and I'm not familiar with the usage, maintenance, or even truly the purpose.

I'm looking for some information on how to actually make use of this system; do I need to fill it with something like you would a Water Softener system? Does this do the same thing as a Water Softener system? Is there specific maintenance that I should be preforming regularly or is this more of a hands off system?

Our property does draw its water from a well, and I have noticed that the water appears to have a high iron content. I haven't officially tested this yet, but we did have to clean green stains out of all the bathroom fixtures, and when we boil water on the stove, there's a rusty brown ring left behind in the pots(it actually left a brown residue on a lot of our baby bottles when we tried to sterilize by boiling). The water appears clear from faucets but is a little cloudy(white) when filling bowls or pots. Would this Acid Water Neutralizer help reduce the iron content if I were able to get it operational again or should I be looking into something else entirely?

1 Answer 1


"Clear water iron" would be a search term to help you understand that side of the problem. While it can be treated, an acid neutralizer is not going to treat it - it needs to be oxidized (aeration/spray or chlorine are typical approaches) and then filtered out.

An acid neutralizer (generally, no idea on your specific model) does pretty much what it says, often by using a bed of limestone chips (low tech and simple) or possibly a more soluble alkaline chemical. The probably closely related "APUN100-LM" manual does say "Media, calcium carbonate" which is fancy language for limestone; you'll just need an appropriate size (too coarse, not enough surface area - too fine, doesn't stay in the filter housing.) Actually, I think that -LM nomenclature simply means "less media" (it's shipped without any, you source it locally) so that probably IS your manual.

Since the green stains in the plumbing are from your copper pipes corroding, it's probably a good idea to get that working again or functionally replaced - especially if your copper plumbing is old enough to have been assembled with tin/lead solder. Acid water dissolves copper and lead, which both poisons you and will eventually perforate your pipes.

  • I know I'm asking more of an opinion piece now, but, what do you think the level of difficulty would be for getting something like that up and running again, assuming of course that there is nothing functionally wrong with the system as it sits now? If it needed to be serviced would I be calling a plumber or a special service technician? May 19, 2016 at 15:27
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    I think you probably open it up and add limestone, as shown here: multimedia.3m.com/mws/media/793622O/… which seems pretty DIY friendly to me. And get some pH test strips.
    – Ecnerwal
    May 19, 2016 at 15:29
  • I just saw your edits, thank you. I will take a look at that LM Manual and see if I can get an idea of the difficulty of getting it up and running again. I'll also look into the clear water iron. May 19, 2016 at 15:29

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