Well filtration fun in MD -- acidic hard water

[Jasonir129]

Hi guys, new to the forum. Lots of helpful stuff here, looking to get some feedback on well filtration setup. I know you guys say there's no "one size fits all", so I'll give details from our water testing. The current setup is just a cartridge sediment filter and a calcite based neutralizer. I’m looking to replace it all and set up something new. Not looking to save money/cut corners on my setup, especially with a toddler and another kid on the way, but I do plan to do my own install (I’m pretty handy and have some minor plumbing experience).

During the inspection period of buying our home we did several water tests which are attached. The high-level summary:

The VA (basic) water test:
pH: 5.39
total coliform: failed (already shocked the well)
Nitrate: 6.8
Nitrite: 0
Turbidity: 6.91
Iron: 0.29
Lead: 0 (all CPVC)

VOCs: all negative

radon in the water: 1960 pCi/L

A filtration sales person did their own tests:
pH: raw 5.5, treated 6.8
Hardness: raw 7, treated 10
iron: raw .75, treated .2
nitrates: 4
TDS: 292
no copper, chlorine or HYD sulfide

I’ve received lots of conflicting advice on directions to go. What I had in mind:

Sediment filter, something for radon in water (likely coconut shell carbon, GAC), neutralizer, softener, and an RO in the basement (with booster pump) that feeds a spigot at the sink, the refrigerator, and whole house humidifier. Anything else recommended?

- For the sediment filter, one company recommended a 5 micron cartridge filter, while another recommended a backwash filter with filter-ag. They seem like totally different beasts.
- For the neutralizer, similar situation, one company recommends a soda ash system while another says to avoid that because they’re high maintenance and we’ll be fine with calcite+corosex and the softener will knock out the added hardness.
- Radon in the water – one company was pushing aerator, another said the level is pretty low and to just do a dual tank GAC setup. I’ve heard (from aerator pushing company) the GAC would need to be in a totally separate area isolated from the rest of the filtration equipment and the disposal of the carbon is complicated. Is this true?
- RO – a friend has a light commercial filter for the same setup I’m looking to do, but I’d guess that huge overkill and we’d be fine with a 50 gpd setup with storage tank and booster pump.

I know this is a lot of questions – I really appreciate any insight you pros can provide.

Thanks in advance!
Jason

 

[Reach4]

pH: 5.39
total coliform: failed (already shocked the well)

An alternative to calcite and maybe corosex is to inject potassium hydroxide or sodium hydroxide. The flow meter in the softener could tell the injector pump how much to inject.

- Radon in the water – one company was pushing aerator, another said the level is pretty low and to just do a dual tank GAC setup. I’ve heard (from aerator pushing company) the GAC would need to be in a totally separate area isolated from the rest of the filtration equipment and the disposal of the carbon is complicated. Is this true?

From my quick search, your radon number was not that high.

total coliform: failed (already shocked the well)

For a deep well, usually that result would be because of sampling techniques. .. not sterilizing the faucet well, and other stuff.

My iron+H2S filter uses Centaur carbon. I don't think it is the same as generic "catalytic carbon". It does well for me. I suspect it would capture radon, but I never had that tested.

A Clack filterAg media tank would not seem to be appropriate. That is for a lot of sediment.

I am not a pro.

 

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[Jasonir129]

An alternative to calcite and maybe corosex is to inject potassium hydroxide or sodium hydroxide. The flow meter in the softener could tell the injector pump how much to inject.

Sure, I'm moderately aware of the injection options (soda ash and lye) but was more looking to see if you guys thought the calcite+corosex would work for me or if I should do the injection system to ensure I get the pH raised to neutral.

From my quick search, your radon number was not that high.

Sure, but I'd still like to do something about it and get it as low as possible. I see there are 2 main ways of remediation, aeration and GAC. Both have pros and cons. Has anyone here installed/lived with GAC for radon removal?

For a deep well, usually that result would be because of sampling techniques. .. not sterilizing the faucet well, and other stuff.

Sorry, this was poorly written on my part -- it failed total coliform, then we shocked, we retested and it's fine now (just acknowledging the result in the report so that UV isn't necessary).

 

[Bob999]

Sure, I'm moderately aware of the injection options (soda ash and lye) but was more looking to see if you guys thought the calcite+corosex would work for me or if I should do the injection system to ensure I get the pH raised to neutral.

I have tried both calcite+corosex and soda ash injection. In my situation I found soda ash injection preferable because the dosing is easily adjusted and, for me, once set has been very stable. I am careful when I mix my injection solution to carefully measure so that solution strength is a constant.
The problem with calcite+corosex for me was that pH varied widely depending on usage rates. Presumably this occured because water sitting in the tank had more time for the pH to be adjusted and then during times of high usage the pH was not raised as much.

 

[Jasonir129]

I have tried both calcite+corosex and soda ash injection. In my situation I found soda ash injection preferable because the dosing is easily adjusted and, for me, once set has been very stable. I am careful when I mix my injection solution to carefully measure so that solution strength is a constant.
The problem with calcite+corosex for me was that pH varied widely depending on usage rates. Presumably this occured because water sitting in the tank had more time for the pH to be adjusted and then during times of high usage the pH was not raised as much.

That was my main concern on calcite approach was I've heard that higher flow rates don't get the pH bumped up to neutral with a lower untreated pH like ours. One of the companies is insisting the corosex ups the rate of raising the pH. We're definitely not opposed to injection approach though.

On the flip side if we do an aerator for the radon (Overkill I know, but peace of mind) that it also might bump up pH by around a point which definitely helps and possibly makes calcite more reasonable?

 

[Jasonir129]

Hi everyone, just wanted to revisit this thread again. I got swept away with other house things and let this fall by the wayside. We've already added a softener (valve is fleck 5810SXT) that I installed, however we're looking to get a sediment filter and an acid neutralizer. We currently have one of the 10" big blue filters and a calcite neutralizer. From what we've previously discussed the injection seems to be the best option given our low pH (5.4). Thanks in advance!

Also any recommended dealers would be appreciated!

 

[ditttohead]

Injection is more controlled, but a little more maintenance. It also does not add hardness so additional softening capacity os not a concern. Regardless, raising the pH is good in you application, if you have copper plumbing you will still want to test for copper in the water after treatment. pH is only one of many factors when considering how corrosive water is.