Pool Acid Dose Calculator - How Much Acid To Add To Pool?
Wondering how much acid to add to your swimming pool? Use this calculator to quickly work out how much acid is needed to properly lower the alkalinity and pH in your pool.
Works with hydrochloric acid and sodium bisulphate (dry acid).
Pool Acid Dose Calculator
How Do I Use This Pool Acid Calculator?
To use this pool acid dose calculator, you'll need the following information about your pool and it's water chemistry:
- Pool volume
- Current alkalinity
- Current pH
- Desired alkalinity OR pH
- Acid product you will use (hydrochloric acid or sodium bisulphate)
- Acid product concentration
Once you enter this information, the calculator will automatically work out how much acid you need to dose to hit your desired pH or alkalinity.
If you selected a target pH, it will also let you know the resulting alkalinity after dosing acid, and vice versa.
How Much Hydrochloric Acid Do I Add To My Pool?
The amount of hydrochloric acid that you need to add to your pool depends on a variety of factors, but lets look at an example swimming pool.
For a swimming pool with a volume of 50,000 L, current alkalinity of 150 ppm and current pH of 8.3, the owner would need to dose 540 mL of hydrochloric acid (with a concentration of 30%) to achieve a target pH of 7.5.
The final alkalinity would be 140 ppm.
For a swimming pool with a volume of 80,000 L, current pH of 8.0 and current alkalinity of 130 ppm, the owner would need to dose 1,700 mL of hydrochloric acid (with a concentration of 30%) to achieve a target alkalinity of 110 ppm.
The final pH would be 7.1.
As you can seem the amount of hydrochloric acid required is quite variable and that's why I've made this calculator; so you can enter all of the details of your pool and work out the exact amount you need.
Gone are the days of relying on rules of thumb and dosing guides that don't apply to your pool!
How Much Dry Acid Do I Add To My Pool?
How much dry acid (sodium bisulphate) you need to dose into your swimming pool depends on a few different factors (hence why I've made the calculator!), so let's look at 2 examples.
For a pool with a volume of 60,000 L, current alkalinity of 140 ppm and current pH of 8.5, the owner would need to dose 830g of sodium bisulphate (at a concentration of 92%) to achieve a target pH of 7.5.
The final alkalinity would be 129 ppm.
For a pool with a volume of 90,000 L, current pH of 8.1 and current alkalinity of 120 ppm, the owner would need to dose 2,300 g of sodium bisulphate (at a concentration of 92%) to achieve a target alkalinity of 100 ppm.
The final pH would be 7.1.
How Often Should I Add Acid To My Pool?
In an ideal world, you would never need to add acid to your pool. Unfortunately, our pool is out and open to elements, affected by swimmers, wildlife and other pool chemicals.
All of these cause fluctuations in your pool's pH and alkalinity, which may need correcting with an acid dose.
There is no set schedule you should be following when it comes to acid, but you should dose it as required. Measure the alkalinity and pH in your pool at least weekly, and dose acid whenever you start to see high pH or high alkalinity.
Fail to do this and you may see reduced chlorine effectiveness, corrosion of pool equipment and pipes, plus increased calcium scaling to name just a few problems.
As we've discussed before, it's very difficult to lower pH without chemicals, so every pool owner should have some acid on hand in case the water chemistry starts to drift away from the recommended ranges.
Noticed any issues with this calculator? Have some feedback? Please let me know over at the contact page!
A chemical engineer by trade, Louis is committed to debunking myths in the pool industry by explaining the underlying chemistry and making it accessible to all.