Even if you are new to pool ownership, you are already probably pretty well acquainted with chlorine and muriatic acid since these are the two most important chemicals for keeping your water sanitized and safe. While these are important – chlorine and pH level are the things you need to monitor most closely – they aren’t the only water quality levels you will need to be aware of. Another important measure is the total alkalinity (TA) of your water.
The measure of water alkalinity just refers to the amount of acid in the water it can neutralize. Alkalinity is important since, when it is within appropriate ranges, it acts as a sort of “buffer” and helps to keep pH levels stable and in balance. When out of balance, it will not provide this buffer service and can lead to degradation of physical tool parts.
Pool alkalinity is measured in terms of ‘Total Alkalinity’. Specifically, when you test your water for total alkalinity, you are looking to regular bicarbonate alkalinity and ideally, your levels should be between 80-120/ppm.
With this in mind, there are three stages of alkalinity i.e. too low, too high and perfect. Highly alkaline water can result in metal corrosion, pool staining, scaling and chlorine inefficiency. Extreme pH levels can also be harmful for the human body.
What Causes Problems with Alkalinity Balance?
The pH balance can shift drastically between these levels depending on various factors such as geography, water quality, additives and many more.
Most commonly, people will be dealing with water that is too alkaline, rather than not alkaline enough. This often happens as a result of using too much sodium bicarbonate in attempts to balance pH. When alkalinity levels are too high, it can cause damage to your filter and plumbing system. An obvious indication that your pool is too alkaline and out of balance is cloudy, murky water or Murky water or calcium deposits. The easiest way to avoid this is to make sure to only use as much as is prescribed on the specific chemical you are using for pH management. It is really easy to overdo it.
Another source of alkalinity issues comes from your water source. Each city, municipality, etc., is required to provide full disclosure of the chemicals and substances in the water and the levels they can be found at. Some water sources are a lot more or less alkaline than others and you may need to adjust your chemical usage to account for this. You can request a copy of water testing results from the city or company that provides your water and this will give you invaluable information when it comes to troubleshooting alkalinity problems.
Pool Alkalinity and pH
As we briefly mentioned above, alkalinity is most important because of its relationship with pH levels. It might be best to think of them as akin to close relations like cousins because they influence one another. Scientifically, pH refers to the concentration of acid protons in the water. Alkalinity refers to the ability of said water to neutralize the acid. There is a chemical process whereby ions in alkaline substances take on acid protons into their molecular structure. This means that the acid protons are not “free acid” which would act to lower the pH of the water.
Handling High Alkalinity
Here we are going to focus on how to reduce high levels of alkalinity in your pool water since it is so much more common than having too low alkalinity. Low alkalinity is an issue pool owners do sometimes face and this can make it hard to keep pH in balance, but it is also incredibly rare. There are a lot of different ways you can go about reducing the level of alkalinity in the water, but the most effective way is to use muriatic acid. This is also convenient since this is what many pool owners use in tandem with chlorine to keep their water properly sanitized. It should be noted that muriatic acid – whether in liquid, granular, or powdered form – is a highly corrosive substance that can damage eyes, skin, and clothes. You need to take appropriate safety precautions when using any pool chemicals.
Before doing anything, you will want to turn your pool pump off and keep it off for at least an hour. There will be instructions on how to use the acid to lower alkalinity and you want to make sure that you use absolutely no more than is called for in the manufacturer’s instructions. You want to get the alkalinity below 120/ppm. If you are using powdered or granular acid, you will need to dilute the acid in a large bucket of water before putting it in the pool. Most recommend that you pour the acid or diluted acid mixture into the deepest or center part of the pool where it can make its way through the entire body of water. Let the chemicals mix with the water for about an hour and then you can turn the pool pump back on.
The pool water is still not safe to swim in. You will want to let the pump run for about 5 hours. This should help the acid get fully circulated and absorbed into the water. Then, you want to test your water to see how your alkalinity levels look. Once your levels have dropped back within range, you can open the pool for use again.
Chemical balance is one of the most important parts of managing a pool of any size – whether commercial or residential. Alkalinity essentially refers to the number of alkaline substances in your water that are available to neutralize the acid. Due to the chemical structure and nature of alkaline substances, they have huge effects on the pH levels of the water, so problems in one area often go hand-in-hand with issues in the other. Most commonly people deal with high levels of alkalinity. This can be easily managed using the same muriatic acid that you use to keep your pH levels in balance.
Almost all commercially-available pool acids will have instructions for how to use the product to reduce the alkalinity in the water to below 120/ppm. Once you have identified the problem, it is pretty easy to fix, it just takes a little detective work and some patience. Adding chemicals to a large body of water like a pool does not have an immediate effect. It takes time for the chemicals to be absorbed fully into the water and then to work to bring down the alkalinity levels.
Wrapping Up
A dip in the pool in hot summers is what memories are made of, but it’s important to get alkalinity in proper balance before you can really start enjoying your pool. Stable pH balance can truly enhance the experience of pool ownership.