home water treatment (pH)

[Mike Schloss]

I have a question for anyone with knowledge of home water treatment. I live in a home where water is provided by a well (no town water). When we had the water tested originally it was slightly acidic but not enough to warrant treatment. After we lived here for a while we determined that the pH changes over time and in the winter the water is acidic enough to warrant treatment. The water is also quite hard so we had a softener installed by a local outfit. We discussed the pH issue with the same guy and his recommendation was to install another tank (like the softener) and this one would be filled with marble chips. Water flowing through the tank would dissolve the marble and neutralize the acidity. The softener would then remove the added calcium. There would be a loss of pressure due to pumping the water through the calcium. This would be in addition to the loss of pressure due to pumping the water through the softener. Since our water pressure is already lower then what we would like I asked him to look into something else. He said that he could install a chemical injection system that would meet our needs but it would require periodic servicing to maintain proper pH. The servicing would be at add soda ash and water to a storage tank periodically and occasional stirring of the tank. Also, I would need to adjust the concentration in the tank to regulate the pH of the domestic water as the water from the well changed over time. The system was installed so that the soda ash solution is injected into the pressure tank and the system ran OK for about a year (warranty was for a year). There has been a repeated buildup of crud (soda ash) on the pump fittings and the installer explained that this is normal. I asked if we could use more soda ash in the tank and reduce the pump speed or stroke to reduce the frequency of having to refill the tank. I was told that according to the installers contact at the pump company that the pump should always be run at full speed and full stroke and he would/could not provide an explanation as to why this might be true. Recently we noticed that the pump was no longer pumping and is no longer under warranty. Upon investigation of the service manual it appears that this pump requires annual service (replace diaphragm). I am beginning to come to the opinion that this pump is a piece of junk. Questions for the readers are:

1) Could anyone make a recommendation for a new pump? 220V >8gpd @ 80psi I can do simple plumbing and electrical tasks myself. Any reason not to do this myself?

2) Soda Ash seems a poor choice for reducing the pH. The stuff that I get in the 50lb sacks seems to have a fair amount of insoluble crud that collects at the bottom of the tank and makes it difficult to stir. Wouldn't sodium hydroxide (lye) be a better choice. I know that I need to be (more) careful with this (goggles and maybe gloves and/or respirator).

Any recommendations?

[Pop]

... | | 1) Could anyone make a recommendation for a new pump? 220V >8gpd @ 80psi | ...

8 gpd? That's awfully low isn't it? 80 psi? That's awfully high; very high, in fact.

Typos maybe? Or do I misunderstand something?

Pop

[Edwin Pawlowski]

Check out specw of pumps at places like

or or your local plumbing supply. I think you want 8 gpm, not gpd. 80 psi is about right for what you are doing as there will be losses on the other end.

I treat industrial boilers with sodium hydroxide. No way am I going to introduce it into my home water system. It is very caustic even in dilute forms. I don't know if soda ash is a good choice or not.

[Mike Schloss]

No, this pump would be injecting a chemical solution into the line from the main pump and into the pressure/holding tank. The reserve tank is ~200gal so if it were running at the max then the tank would need a refill more than once a month. And I am not sure if the 8gpd accounts for the duty cycle. The feed pump only runs when the well pump is running.

Not if it is going into a pressure tank set to trigger at 70psi. And after the loss due to the water softener and the rest of the system, my shower still isn't as strong as I would like.

Hope this clears things up.

Mike

[Mike Schloss]

I'll check those out.  Thanks.  And I think that I do want 8gpd and not

8gpm.  This is the chemical feed pump.  The well pump does the "heavy lifting".  This pump just injects the chemical solution while the well pump is running.  Again, this is a replacement for an existing 8gpd pump that is non-functional.

2) Soda Ash seems a poor choice for reducing the pH. The stuff that I get in the 50lb sacks seems to have a fair amount of insoluble crud that collects at the bottom of the tank and makes it difficult to stir. Wouldn't sodium hydroxide (lye) be a better choice. I know that I need to be (more) careful with this (goggles and maybe gloves and/or respirator). I treat industrial boilers with sodium hydroxide. No way am I going to introduce it into my home water system. It is very caustic even in dilute forms. I don't know if soda ash is a good choice or not.

Sodium Hydoroxide is a lot more caustic than Soda Ash.  All this means is that I can mix up a fixed amount of chemical solution with a higher pH and run the pump at a lower setting resulting in less frequent refills.  I understand that I need to be more careful when mixing.  My water is acidic.  I can add a lot of a weak base or a lesser amount of a stronger base.  The end product should be close to neutral before it exits the pressure tank (closer to neutral than it is now). I also supect that I will be dealing with less insoluble crud with lye rather than soda ash.  Or perhaps not.  That is why I am asking...

[Ray]

Just how acid is the untreated water? Do your neighbors have the same problem? Do you know why the water is so acid?

Mike Schloss wrote:

[Mike Schloss]

If I recall correctly it was about 6.2 last winter before treatment. Neighbors don't appear to have the same problem but well issues can be extremely localized. For example, our two neighbors across the street have had problems with their wells due to lack of volume. I think that they may be at 4 or 6 gpm. One of the neighbors had to hydrofracture to get any flow. Our well on the other hand delivers 24 gpm without a problem. The adjacent lot couldn't find a suitable well in two trys.

As to why the water is so acidic, beats me. The explanation I got from the local treatment guy is that if the water drains through lots of organic matter then it can pick up significant acidity. He said that it wasn't at all unusual for the pH to vary over the course of the year with winters being the worse time for acidic water.