Balanced pH keeps your water comfortable, protects equipment and helps your sanitizer work. In many areas, fill water starts with high pH and high total alkalinity, so lowering both is one of the most common adjustments Royal Spa owners make.
There is no single formula. Hot tub size, fill water, bather load, how often you soak, water temperature and your overall routine all affect how much adjustment you need. Always follow the ideal ranges on your test kit. For background, read 4 things that affect hot tub water chemistry.
How to Lower pH and Alkalinity
- Test first with test strips or a test kit.
- Add pH/Alkalinity Down. Add 1 oz of pH/Alkalinity Down per 100 gallons of water (500 gallons = 5 oz). Run the jets for several minutes to mix.
- Retest after about 15 minutes. If pH or alkalinity is still high, add 1/2 oz per 100 gallons (500 gallons = 2 to 2.5 oz) and run the jets again.
- Repeat until both readings are within your test kit’s ideal range.
- Check again two days later and fine-tune if needed.
Do not add pH Up and pH Down on the same day. That causes “pH bounce,” where readings swing back and forth.
Keep a Log
Write down how many ounces it took to balance your water after a fill. Next time you change your water, add that amount at once and you will reach balance much faster. For example, if it took 10 oz over the first day or two, add 10 oz at the next refill.
For more on water care, see the Royal Spa Operation and Care Guide or call us at 317-781-0828.
Frequently Asked Questions
Why does my hot tub pH keep rising?
Hard or high-alkalinity fill water is a common cause. Lowering total alkalinity along with pH helps the pH stay put.
How long after adding pH Down can I use my hot tub?
Wait until the product has mixed and dissolved with the jets running, then retest to confirm your readings are in range before soaking.
Can high pH make my water cloudy?
Yes. High pH and alkalinity are common causes of cloudy water. See how to fix cloudy hot tub water.
