Low pH

I recently bought a home with a well. The water tests showed a low pH level (4.9). There is a soda ash feeder tank with a Chem Tech Pulse Feeder 100 series set up prior to the pressure tank. Even if I crank the feeder level up to the highest setting, I can't get a 7.0 pH level using a pH test kit. Am I missing something or should I be concerned? I have moderatly hard water also if that is a consideration.

Try Sodium Hydroxide, Carefully

Soda ash is a fairly weak base. And pH 4.9 is a long way to go to get to 7.0. I don't have my references to make a calculation.

You might want to get a reliable pH pen-type meter and some standards (cost less than $100). Then try solutions of sodium hydroxide (lye). Get the straight stuff, not some kind of drain cleaner with other stuff in it.

The best pH standards are the little pillows of powder or tablets that you mix with water. I suggest pH 4 and pH 7 standards for your meter. The little liquid foil packs are lousy because they leak and are expensive.

Sodium hydroxide is perfectly safe in water and it doesn't add hardness. Try just a little to start with as I can't give you a calculation right now. You might try a dilute solution in a test.

Mix about 1/4 tsp in a quart of water. Then add a little at a time to your water to see how much it takes to bring a gallon of your water up to pH 7.0. Once you have determined the correct ratio, you know how much to add to your feeder.

Use glass, plastic, or stainless steel for handling. DO NOT use anything aluminum.

I'm gonna try it

Thanks Bob,
A few more quick questions; Does lye have a taste after it's diluted? Also, I found a digital tester online. It's a Hanna CHECKER 1 pH TESTER/METER. It comes with the calibration kit, pH 7 and 4 as you recomend. Is there a need to buy the "Storage Solution" for the probe? I really appreciate your advice!

No need to buy storage solution. You can use a little diluted pH 7 calibration solution. The critical part is to keep it moist with something that won't create solids.

Lye is sodium hydroxide. When it neutralizes the acid it becomes a very small amount of a salt of the acid that was in the water. So if the acid is hydrochloric acid (HCl), it will produce NaCl and water. You won't be able to taste the very small amount of salt that it will produce.

Because Sodium Hydroxide is a much stronger base, it will take less than the soda ash you are using, so there will actually be less salt in the water.

When I am referring to salt, it is not limited to sodium chloride. It is whatever is the result of neutralizing the acid with the base. If your low pH is caused by sulphuric acid, then you will get sodium sulphate.

If you don't have a correctly sized retention tank, it probably won't work no matter what caustic you use.

I wouldn't suggest a solution feeder system, they require constant baby sitting etc.. I would suggest a mixed bed backwashed sacrificial mineral filter although they add hardness to the water. They are automatic and the only maintenance is adding new mineral maybe twice a year; depending on how much water you use. The mineral is inexpensive and harmless; unlike soda ash or lye. With a filter, you don't need a retention tank and a filter takes up much less space. A filter usually will cost less than a solution feeder and retention tank although you already have the feeder and solution tank. The maintenance on the feeder can be quite frequent and depending on your family size, volume of water used, you may be mixing solution very frequently.

I have sold many acid neutralizer filters over the years and no one with one would ever go back to a solution feeder system.

The response to the original poster was in the context of trying to make a chemical feeder work. I don't know without some searching how low a pH the marble chips will handle, or what the hardness contribution will be with pH 4.9 water.

It doesn't take a lot of contact time for sodium hydroxide to neutralize acid. It does take mixing. Elbows and small pipe promote turbulence and mixing.

The ChemTech Pulsafeeder pump injects chemical only during a portion of its cycle. For example, if you have 12 cycles per minute, and a 12 GPM pump, you will get only one shot of chemical per gallon of water. Part ot that gallon will contain all of the chemical, and part of it will contain no chemical. You need enough mixing time and volume to get that chemical mixed. A bladder tank doesn't do it. You need a flow-through setup of pipes or tank that will have a volume of two to five times the volume of water that is pumped in one cycle of the chemical feed pump.

You usually want to operate those diaphragm chemical feed pumps near their maximum flow, and adjust the chemical level by adjusting the concentration in the supply tank. When those pumps are turned down, they have very erratic flow rates and it is difficult to adjust the concentration of the mixed water/chemical.

The problem is I do know, although it's been a long time since I set up or serviced a solution feeder, and what you are telling him isn't the way it's done in residental applications. Example, you want the pump set at about 50% to allow adjustment and you control the solution strength and volume injected. IIRC, that is the instructions that come with the pumps. Also, your volume of water etc... he needs a retention tank to provide adequate contact time; usually stated as a minimum of 20 minutes until the water exits the first fixture. The is dictated by the peak demand of the house, not the output of the well water pump.

As a dealer I would never want lye around a household in today's society. Since most folks with a feeder never get them to work correctly, I suggest he go with a different type acid neutralizer; he really wants to protect his plumbing and fixtures and probably doesnt care much how that is done but would want the least fuss and expense. So as a knowledgeable sales person in the industry, I suggest a means to solve the problem rather than engineer something together that may or may not work.

Low pH - Treatment Options

Thank you both for the advice. In the short term, I'm going to take Bob NH's advice and get a more accurate pH tester. (I just ordered one on ****) I'm a little short on cash, so I may want to carefully experiment with the Sodium Hydroxide until I can evaluate a more "low maintenance system" like Gary discussed.

Gary,
You are correct. I would prefer not to deal with a lot of "fuss" with mixing chemicals and adjusting the system, but I didn't think that was an option with the extremely low pH. Do you have a particular make and model acid neutralizer filter you recommend? It's only me and my wife in the house. I'm not immediatly concerned about the hardness factor, unless it's going to be a dramatic difference from the current soda ash system. I could add a softener later (if that's an option with this type of treatment). The water doesn't seem hard at all right now. I should also note that I started this thread with slightly incorrect data. The pre-treated pH is actually 5.4. I read the water test report incorrectly.

I have successfully treated water as low as 4.6 pH with downflow, backwashed AN filters. Upflow won't do that. You have to know the hardness in the raw water so to not 'cement' the mineral.

To do that the dealer has to know what they are doing. A backwashed AN filter is a top dome hole polyglass tank with a backwash only control valve on it. You can use any control valve brand and model as long as it is capable of servicing the size of the tank that has to be used and provide the proper backwash flow rate for the volume and type of mineral used. That volume depends on the pH of the raw water and the peak demand gpm of water used in the building. Very simple and dependable with very little maintenance. I sold one yesterday, calcite only not mixed bed, for a delivered price of $600. That was with a Clack WS1 control valve with by-pass valve.

In your case, there will be 6-10 gpg of hardness added to the water and you can add a softener at any time; just plan on its space requirement when you install the filter.

Without a retention tank, I seriously doubt you will get your feeder system to provide 7.0 pH very consistently. It will probably be all over the scale and on the high side. Too much soda ash usually causes a slimy/thick feel to the water, I don't know about lye; since BobNH suggested its use, he should.

You could use a static mixer (a special piece of plastic pipe with baffles etc. in it) but IMO (I've never done it) you'll probably have a real tough time getting the dose and mix strength set correctly without a retention tank. I suspect you already know that from many attempts at getting the thing to work. Soda ash will work fine for your 5.4 pH. All you have to do is get the mix strength and dose right and prevent the precipitation of soda ash out of solution in the bottom of the solution tank, and then not run it out of solution. And keep the injector and check valve (ceramic balls) clean so it/they open properly and on time.

To follow up on my original post, I was able to get a good concentration of soda ash and have been checking my PH over the last eight months. It's been consistently between 6.9 and 7.1... I assume that should be good enough... I've been measuring with a digital ph tester.

It's come time to mix-up the soda ash again.... is there a right way and a wrong way?

Back form the days of having a fish tank…

Co2 will drop the PH of water. A lot of wells where I live have a lot of Co2 in them. If you test the PH of a bowl of water that is right out of the tap and let it sit in a bowl for 12 hours on the counter and retest the PH.

I know this has already been thought about!-)