Opinions on Whole House Filter Housing Size and Material

[MG70]

I'm finally getting around to a pex repipe and I'm thinking about installing separate canister type (aka spin-down, sump, etc.) filters for sediment (pre-filter, small flushable), sediment, and iron. The house is on a well, has very high water hardness, but I'm going to try to see if I can get by without a water softener for now (house was built in 1975, I'm the second owner, and there wasn't a softener in it). The small house only has two bathrooms, 1-2 occupants, a tank-style electric water heater, clothes washer, and will have a dishwasher and a reverse osmosis drinking water system. I'm thinking of separating the supply line for the 2-3 hose bibbs, so they won't have filtered water.

Filter housing material. No matter the brand, including AO Smith, GE, Whirlpool, Culligan, Pentair, and the various other brands with names that all send alike, from reading online reviews, it seems that clear or see-through/transparent housings seem to crack quite frequently. I assume it's the material they're made from and the lack of quality control and/or consistency where they were made.

Question 1). Is it safe to say that the non see-through filter housings, like the traditional blue ones, are less likely to crack or fail? Based on experience, do you have a favorite brand and model?

Question 2). Do you think a filter housing with an internal water by-pass is more likely to fail? I've read they can cause problems.

Question 3). Do you believe filter housings with metal thread inserts are more likely to leak as compared to threads on the plastic top itself?

Question 4). Based on my first paragraph, what filter housing size would you recommend for the sediment and iron? 10" X 2 1/2", 10" X 4 1/2"?

Thanks in advance and I hope everyone is having a safe week!

 

[Reach4]

If you can handle the weight, a 4.5x20 has twice the capacity of a 4.5x10. It may be that 4.5x20 is overkill. I think mine are overkill. I ordered that before I decided to put in a backwashing iron+H2S filter at the front end.

What size sediment do you get? Sand particle size, or very fine? Spin down is for bigger stuff like sand. Another kind of front-end filter, where the sediment is big but not a lot of volume, is the wye filter. So it is not as easy to clean out, but may be all you need at the front end.

I like the Pentair DGD cartridges.

If you use a spin-down after the pressure tank, consider also having a 4.5x10 after the softener. Some filters, like I think the Pentair Big Blue, which I have, will accept a 10 or 20 inch sump interchangeably.

Make sure to keep an extra o-ring on hand, in case you cannot get the old o-ring back in. Leaky seal means your water system is down. Maybe with the cartridge filter with the built-in bypass that would not be critical.

I suggest a lab water test. See what you are dealing with for iron, pH, hardness, and more.

 

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[MG70]

Reach4, thanks for your reply!

There I go again screwing up my terminology, in addition to anticipating myself. I bought a spin down filter when I bought a Reverse Osmosis system back in 2023 or 2024. I have no problem using the larger filter but ease of availability and cost are considerations.

Water analysis is from the only time I had it tested, pre-purchase. The well was drilled in 1975, hadn't been used for at least 3 years, the well casing head was bent, the cap was obviously not sealing, and the water sample was collected at a bathtub spout fed by old copper pipes.

The house is being replumbed with Pex. The only old plumbing staying (for now) will be the section from where the water enters the house to just above the main shutoff where there's a hose bibb that will be kept and used for the disinfection any day now.

Initial Test Results

Bacteria, Total Coliform >200 cfu/100ml

Bacteria E. Coli <1.0 cfu/100ml

Hardness: 874 mg/L

Chloride 595 mg/L (edited, MCL 250)

Fluoride <0.20 (edited MCL 4)

Nitrate 3.33 mg/L (edited, MCL 10)

Nitride <0.20 mg/L (edited, MCL 1.0)

Orthophosphate <0.20 mg/L (edited, MCL blank)

Sulfate 9.02 mg/L (edited, MCL 250)

Iron 0.58 mg/L (edited, MCL blank)

Ph 7.35 SU (edited, MCL blank)

Turbidity 8.35 NTUs (edited, MCL 9.99)


Hardness: I'm going to avoid installing a water softener for now, and get in the habit of flushing the water heater often and regularly (it's still not installed). The other appliances are cheaper to replace. I have not researched if there's a way to remove mineral deposits from the various appliances, but I plan on doing that.

Chloride. Reverse Osmosis is one of the better ways to remove it and I plan on installing a system (already purchased). There are farms nearby that likely use chemicals with salt and the state still uses salt on the roads in winter.

Iron. There's a chance that after disinfecting the well the iron level and turbidity both decrease. If it's still high after that, then I'll plan on using a cartridge style filter.

Ph. Seems to be within the EPA recommended level. One less thing to worry about.


I haven't decided on the exact set-up for the filters but I need to get this done right away. It seems I need to wait a few days after disinfecting the well before having the water retested again. Only then will I know exactly what I'm dealing with but I'm pretty sure I'll have to set up one or more sediment filters to address the iron and turbidity.

1). I'm thinking a 10" X 4 1/2" or larger Sediment filter, and possibly an Iron filter, for the line feeding water heater, appliances, sinks, and the Reverse Osmosis Filter.

2). Possibly a second sediment filter for the line feeding the Reverse Osmosis filter (ISpring RCC7RO75 or something similar), which I'm planning on installing in the basement with the think supply line going up to the kitchen sink.

3) Separate supply line with No filters feeding Hose Bibbs and Toilets


As always, suggestions are appreciated.

Thanks in advance!

 

[Reach4]

Sulfate. Reverse Osmosis is one of the better ways to remove it and I plan on installing a system (already purchased)

https://www.epa.gov/sdwa/secondary-drinking-water-standards-guidance-nuisance-chemicals shows a 250 MCL for sulfate-- much different than your sulfate "MRL". https://www.epa.gov/sites/default/files/2014-09/documents/support_cc1_sulfate_dwreport.pdf says "Sulfate is an analyte for both surface and ground water NAWQA studies, with a Minimum
Reporting Level (MRL) of 0.1 mg/L." I don't know the usage of minimum reporting level. My sulfate is 134.

Iron 0.58 mg/L (0.05)

A cartridge filter is not a good way to deal with iron, unless you first oxidize the iron (with chlorine or H2O2) first.

A softener can deal with iron. If using that, which I would if you don't have H2S smells, there is only a little extra treatment that you need to do to help the softener.

H2S is hard to test for, but your nose does a good job of deciding if it bothers you.

Hardness: 874 mg/L

Holy chit. That is 51 grains. It used to be that a softener before an RO was highly recommended to help the membrane life. With your iron and hardness, consider a softener.

If you have access to digging equipment, you could consider a "dry well" for the softener drainage.

 

[MG70]

Reach4,
You're absolutely right and thanks for the added info.! I'm sorry for listing MRL (Method Reporting Limit, amount at which lab instrument used is unable to detect the substance) as opposed to MCL (Maximum Contaminant Limit). I've corrected my post above to reflect the MCLs for my lab results.

I've disinfected the well and replaced the well cap with a sanitary well cap, sanitary seal cap, etc., and am waiting at least 5 days before another water analysis. I need to call the best lab around here, which coincidentally was the one who performed the first analysis, to find out if I need to pick up one of their collection bottles or if I can buy and use something closer to me so I don't have to drive out there twice.

If and when I need to dig a dry well, finding someone local with the equipment and knowledge shouldn't be difficult, as a matter of fact, there's a good chance my closest neighbor has it.

Thanks again and I hope you have a safe week!