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The Pool Chemical Calculator: The guide for beginners

Getting your pool chemistry dialed in is a major piece of the puzzle when it comes to pool maintenance.

Nobody wants to mix and match different (highly potent and potentially volatile) chemicals at random and dump them into their pool water, hoping that this chemical concoction will do something – but that’s closer to what a lot of people to with their pool chemical calculations than you might expect.

Anytime you’re talking about something as powerful as chlorine (and a handful of other chemicals you can use to treat and clear your swimming pool) you need to treat it with a lot of respect and a lot of caution.

You need to use the right pool chemical calculators and calculations to get your chemicals dialed in perfectly – and that’s what we are here to help you with.

Below we are going to go through the ins and outs of pool chemistry, using pool chemical calculators to make quick work of measuring your chemical additives, and a whole bunch of other details that help you feel a lot more confident treating, shocking, and sanitizing your pool.

Let’s get right into it!

The Basics of Pool Chemistry

Before we go into the nuts and bolts of pool chemical calculators or pool chemical calculations it’s important to touch on the two fundamentals of pool chemistry itself.

Everything you do when it comes to chemically treating your pool will revolve around two specific things – the balance of central elements in your swimming pool water (four of them in specific) and the sanitation of your pool water as well.

Chemical Balance in Your Water

In the water balance department, the four elements you are looking to keep in perfect harmony are:

When you are trying to balance out your water with chemical treatments these are the four fundamental elements that you are going to want to try and wrangle with. These are the details you’ll want to test for, and the information that you get on your test strips will let you know exactly what you need to do to bring better balance to each of these four components.

As far as your pH levels are concerned it’s important that you shoot for a range of between 7.2 and 7.8 in your swimming pool water as consistently as possible. Anything that dips lower than 7.2 will need a pH enhancer added and anything above 7.8 will need to have corrective action taken to bring that back down).

Overall alkalinity levels should sit somewhere between 80 and 120 parts per million (ppm). Again, anything that dips lower than 80 ppm needs a boost in alkalinity and anything higher than 120 ppm needs to have corrective action taken.

Calcium hardness levels should rest between 150 ppm and 400 ppm. Lower levels of calcium hardness can be treated pretty easily, but if you have higher than 400 ppm calcium hardness levels it can be a little trickier. You can use a mineral sequestering agent or add more water to your pool to dilute things – but than the rest of your core element balances may get kicked out of whack, too.

Finally, cyanuric acid levels should sit between 20 ppm and 100 ppm. This is the most popular chlorine stabilizer you can find on the market today and it does a fantastic job when it is added in the right quantities. If your CA levels are all over the place, though, it’s important to get a handle on things in a hurry or your pool chemistry can nosedive faster than you would have thought possible.


Three core chemicals are going to be used in the sanitation of your swimming pool – chlorine, bromine, and biguanide.

It’s also to remember that you are still going to need a pool chemical calculator on hand if you have a saline pool. You’ll still have chlorine in your pool, it’s just that the saltwater chlorine generator built right in is going to handle the heavy lifting for you – though you’ll still have to balance it every now and again.

Chlorine levels from a sanitization standpoint should always sit between one and 3 ppm. Bromide is a little bit weaker, which is why you want to add between 3 ppm and 5 ppm to fully sanitize your pool. Biguanide is going to need between 30 and 50 ppm to get the job done right.

Of course, if your pool water is really struggling – or if it’s been a while since your pool water has been maintained – you’ll need to add a quick shock to the mix to clear things in a hurry.

Some pool owners recommend shocking your pool every week, others recommend shocking it every other week, and others still try and avoid having to shock it at all. It really all boils down to balancing and monitoring the chemistry of your pool water as well as taking into account individual factors like how often the pool gets used on any specific weather conditions – like a lot of rain, for example – that might shakeup your chemistry composition.

It’s also not a bad idea to shock your pool ahead of and immediately following a big pool party, when you are running low on sanitizer, or if your pool is at any point in time starting to turn green or has already gotten a bit of an emerald hue.

Using Pool Chemistry Calculators

There are a lot of popular pool chemistry calculators out there to pick and choose from, and finding one that suits your needs perfectly is going to be a pretty simple and straightforward process.

At the same time, there are a couple of things you want to know about using pool chemistry calculators before you dive right in (so to speak).

For starters, you’re going to want to make sure that the calculator you are using is easy to navigate, easy to leverage, and as accurate as can be. There are some pool calculators out there that have kind of been cobbled together and may or may not provide you with the most accurate numbers possible – and those are the kinds of calculators (ballpark calculators) that you’ll want to avoid at all costs.

Just to reemphasize, anytime you are dumping powerful chemicals into a pool that people are going to swim in you really need to have a handle on your chemistry.

Secondly, you’ll want to make sure that (at minimum) the pool chemistry calculator you are using accounts for these details:

  • Total volume of pool water that you are treating
  • Alkalinity levels (measured by ppm)
  • pH Levels (measured by ppm)
  • Free chlorine levels (measured by ppm)
  • Total chlorine levels
  • Calcium levels
  • Cyanuric acid levels

It should come as no surprise that these are all the same elements we have made a point of highlighting in the guide above. Your pool chemistry calculator needs to account for each and every one of these core elements so that you know exactly what to do when adding specific elements to water or looking to lower different readings to bring balance back to your water.

Obviously, you’ll also want to get your hands on reliable and consistent pool water testing strips.

These aren’t going to set you back a mountain of money by any stretch of the imagination but it is still well worth investing in high-quality test strips all the same.

Every value you punch into your pool chemistry calculator will be heavily influenced by the readings you get from these strips – and that means every bit of chemical that you add to your pool water is going to be influenced by the same.

Also, if you aren’t exactly sure of how much water you have in your pool there are a lot of volume calculators you can use to get very close to that number.

It’s not a bad idea to add smaller amounts of chemicals to your pool and then retest the first few times you’re working with a ballpark volume calculation, adding more as necessary until you have a better feel for what you need to do moving forward.

Remember this – it’s always a lot easier to add more chemical additives to your water and raise specific levels than it is to do the reverse.

At the end of the day though, working with today’s modern pool chemistry calculators really takes a lot of the guesswork – and the math – out of figuring out just how much of each specific chemical needs to be added to your pool and when.

As long as you focus on the core elements that we highlighted above (and shoot for the most accurate measurements you can get when you are testing) you really won’t have much to worry about all. You’ll find that with the right pool chemistry calculator everything sort of falls into place and is a lot easier to manage just as soon as you get the hang of things.

You’ll have your pool sparkling (and safe to swim in) in no time at all!

Posted in pool maintenance

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