Your exclusive Culligan Representative in Halifax Regional Municpality

Facts: pH and Alkalinity Part 2

Hardness is a separate topic; as for water temperature, just keep in mind that colder water is more vicious than hot water (yep – no misprint).

But I would like to spend a few sentences on TDS and alkalinity with respect to pH of your water. Acidic water wants food; it needs to feed on “something”. To come up with the general equation that low-pH-water always eats your copper pipes is wrong!

It’s like “Bears eat humans”! Yeahh, maybe. But more likely when they are annoyed, teased, not treated right and/or have no other sources of food (and I mean the bears). Look at it this way: While the water runs through your pipes in the house and finds enough to feed on, is there a need for the water to necessarily attack the pipes? No, not really!

In this case TDS actually helps. TDS – Total Dissolved Solids (or more accurately the actual weight of those solids) – are mineral salts and small amounts of organic and inorganic matter. If the TDS are too high, the water becomes unsuitable for any type of ingestion.

BUT: high TDS feeds low pH; the “bear” in the water – now you have it. TDS too high – water unsuitable; pH too low – water unsuitable; see I told you: you need us. Bottom line, the balance between the two needs to be maintained for (at least) drinking water purposes.

Finally I would like to hold forth about something you could call an old wife’s tale. What actually is alkalinity? When you ask people around you – of course you need to make sure they have not read this letter yet – and ask this question, about 95% will say “alkalinity is the opposite of acidity”. Buzzer – wrong answer! Alkalinity is often mixed up with basicity but it is not the same.

Let me clean up this old myth. You have either

  • basic water – pH above 7 (scale forming) OR
  • acidic water – pH below 7 (corrosive) OR
  • neutral water – the area in between (e.g. reverse osmosis water)

So what the heck is alkalinity then? Alkalinity is actually a buffer; it is the capability of water to reject or neutralize acidic influences or in other words, its ability to resist sudden changes in pH. Alkalinity naturally occurs through the existence and composition of hydroxides, bicarbonates, carbonates and occasionally borates, silicates and phosphates. It is used to measure how much acidity can be added to water without changing it to basic levels.

Since many factors need to be taken into account, there is no optimum number for alkalinity but regularly 80-120 mg/L (parts per million) are a good indication for a healthy alkaline level.

Now let us quickly bridge back to the pH. If alkalinity functions as a buffer and TDS help feed the corrosive characteristics of low-pH-water, wouldn’t you think it makes sense to test for those parameters first and very accurately before coming up with (possibly toxic) treatment solutions to raise the pH in your water?

Something to think about, isn’t it? And (this is meant to be a promise rather than a threat) there will be more interesting facts coming down this channel in the future.