CO2 and Ph

[dR3ws3r]

It sounds almost crazy, but I tested my water this morning and it has a PH of 8.85 ... and I thought going from 7.15 to 8 was bad. I bought a Hannah PH meter, and calibrated it yesterday as a backup to my Apex PH meter.

I also noticed my water pressure seems to be down lately as well. I called the water authority to see if they can at least give me a heads up to what is happening. I am sure they are champing at the bit to get back to me lol. Oddly the TDS is still the same 57 ppm.

 

[Byron]

As far as I am aware, CO2 has no impact on TDS. Total dissolved solids refers to things like minerals, chemicals, organics, etc that are dissolved in the water. CO2 is a gas, and dissipates out within about 24 hours. Unless your water authority is adding something to increase pH, the CO2 is the reason for the pH shift.

 

[dR3ws3r]

I mean it makes sense to me that with a pretty constant TDS they are not adding things, unless they are adding more of one and less of another to balance out the value. Overall my PH is starting high and going lower if I let is sit in a bucket for a few days, so it isn't CO2 exiting the water in the bucket or my ph would go up. Additionally adding an air stone to the water in the bucket and bubbling the water makes it drop even more, which implies adding CO2 to the water from bubbling.

I spoke with one woman at the water authority this morning and got a similar message as I have received before. It is possible as a county resident that I can get a mix of county water and city water. She worked at the county facility and said the water leaving their plant is between 7.2-7.4 and has been that way for some time. Somebody is supposed to come by and take a sample, which is more than I expected.

 

[Byron]

Additionally adding an air stone to the water in the bucket and bubbling the water makes it drop even more, which implies adding CO2 to the water from bubbling.

This makes sense because the disturbance is increasing the gas exchange and with the very high level of CO2 in the atmosphere these days you may be adding CO2 to the water rather than removingit as the old books used to advise. CO2 produces carbonic acid, thus lowering the pH.

 

[dR3ws3r]

CO2 in your house is always going to be higher than outside as well. Depending on how well your house is sealed, and lots of other things, you can have twice the CO2 measurement or more inside as outside. I think you have about 410 ppm outside. I have seen between 500-750 in my house. I have even heard stories of people who sealed off their A/C ducts hitting over 1000.

 

[dR3ws3r]

Well the guy from the county came by, took a sample back to the office and said the PH was 8.8. The county is blaming the city .. who they get some of their water from. The city doesn't answer their phone. Personally I wonder if our county signed an agreement to purchase X gallons of water from the city daily, if the city committed to keeping county citizens as informed as their city customers? Although that probably amounts to an annual summary of their water measurement with highs, lows and averages. I'm tempted to use remineralized RO/DI water until this "situation" clears up.

As an older person, I guess I'm not that surprised that nobody at the county can actually tell me where my water comes from, but a younger version of me would have been astounded.

 

[dR3ws3r]

I almost feel like I am writing a blog here, but after almost 2 weeks, the ph of my water has remained about 8.9-9.0 which is above the EPA guideline (6.5-8.5). My local water authority has actually tried to help and has had people out testing water in my area. Today someone came by and we chatted for a while. He noticed that the ph is my cul de sac was higher than the adjoining road, and that was higher than that of the main road. He felt that we had a local slug of high PH water and opened up a fire hydrant on my street and let it run for 90 minutes. He didn't have a PH meter, as they aren't given portable ones, so I let him use mine. After 90 minutes he saw 7.39. So hopefully this is indeed the case.

He noted that the reservoir that we get our water from has acidic water and that they add lime to make it more basic before transporting it. He "thinks" it was possible that the city could have accidentally overfed it, and it took time for that water to reach me since I live on a dead end street. I am not a chemist, but if there was an overabundance of lime, wouldn't my TSD (total dissolved solids) have gone up?

I told him how my water, when left to sit out for a few days, tends to have a film on it. He wasn't sure but thought perhaps it was the phosphates that they add to prevent corrosion in the piping. On top of the fact that he said they use copper sulfate at the reservoir to treat for other problems, it kind of disturbs me to think what is really in my drinking water. Here I am worrying about PH when one can only guess what else is in my water.

 

[Byron]

He noted that the reservoir that we get our water from has acidic water and that they add lime to make it more basic before transporting it. He "thinks" it was possible that the city could have accidentally overfed it, and it took time for that water to reach me since I live on a dead end street. I am not a chemist, but if there was an overabundance of lime, wouldn't my TSD (total dissolved solids) have gone up?

This is exactly what I expected. I have a similar issue here in Vancouver, and it is common in many areas in NA with naturally very soft and acidic water. Acidic water corrodes pipes and appliances over time, so they add lime to increase the pH. This does not affect the GH/KH (at least it never has in my water). I would think the TDS would reflect it, maybe it does, since it is being regularly continually added. I have found that once the aquarium is biologically established (this takes a few months) you can do slightly smaller-volume water changes without significantly fluctuating the pH. I had this in my water since 2001. It only really became a problem earlier this year, when they announced an increase in the soda ash to result in a pH close to 9. Up until this I had not noticed issues.