Total alkalinity (TA) refers to the total concentration of dissolved carbonates, bicarbonates, hydroxides, and cyanurates in a body of water.
These are all alkaline chemicals, meaning they have a pH value greater than 7 on the pH scale, putting them on the alkaline end of the spectrum. (We'll go over this in more detail in the next section.)
Most swimming pool testing kits measure alkalinity in parts per million (ppm), which is equal to one milligram per litre of water.
Finally, "pool alkalinity" is another way of saying the same word, referring to total alkalinity as well. The main distinction is that it is only applicable to water in a swimming pool.
When it comes to pool chemistry, there's a lot of misconception between pH and alkalinity, and they're not the same thing, despite common perception.
When you balance the pH in a pool, there are a few things you're trying to accomplish in the reading. For one, you're determining how acidic or alkaline the water is, which is influenced by the components in the water. The scale ranges from 1 (very acidic) to 14 (extremely alkaline), with 7 being neutral.
To put that in context, consider the following:
- The pH of lemon juice is 2. (very acidic)
- The pH level of urine is 6. (acidic)
- The pH level of water is 7. (neutral)
- The pH of sea water is 8. (alkaline)
- The pH of bleach is 13. (very alkaline)
Alkalinity (or total alkalinity) is measured in parts per million rather than on the pH scale (ppm).
Despite the fact that alkalinity and pH are independent of one another, the two nonetheless have a link. The pH of your pool will usually (but not always) correspond to the alkalinity level, which means:
- Your alkalinity will most likely be low if your pH is low.
- Your alkalinity will most likely be high if your pH is high.
To completely comprehend how this works, you must first comprehend the role of alkalinity in your water, which we will discuss next.
To clarify, I'm talking about alkaline on the pH scale, not total alkalinity.) The ideal pH level for your pool water is 7.4 to 7.6.
This preference for alkaline is deliberate, as it is where chlorine works best while also being kind on your skin and pool equipment. There's a little wriggle room here, but not much.
Unfortunately, pH is extremely sensitive, and variations in water temperature, as well as external things such as rain, debris, and even body waste, can quickly throw it off balance.
That's when good ol' alkalinity comes into play.
A pH buffer, which is exactly what alkalinity increasers are, is the solution to keeping your pH level. Alkalinity acts as a kind of armour for your pH, absorbing variations and maintaining a consistent chemistry in your pool.
What Is The Appropriate Alkalinity Level?
Depending on the type of chlorine used, the proper amount of alkalinity (total alkalinity) to have in your swimming pool is between 80 and 120 parts per million.
Anything outside of this will diminish the efficiency of your chlorine and may cause other negative side effects.
