Water Chemistry /
How to Add Alkalinity to a Pool Safely
To raise total alkalinity, test the water first, then use a pool product labeled for alkalinity adjustment and follow the label and equipment manual closely.
Archive date: this article was written for PoolSkimmer on Oct 23, 2026 and given the earlier archive date of Aug 20, 2026 so the blog reads as an organized archive. It was not published on that date.
Adding alkalinity to a pool
The first step in raising total alkalinity is to verify it is indeed low. Once confirmed, an appropriate pool product can be used in accordance with the maker’s instructions. The object is to bring the numbers up without upsetting the pH or making a water chemistry issue worse.
Pre-treatment checks
A quick look at the water is in order before any treatment is applied. There are other matters that could skew the results:
- Run a dependable test on the total alkalinity.
- Check the pH as well; the two are interrelated.
- Verify the pump is running and circulation is as it should be.
- Inspect for a dirty skimmer basket, cloudy water or debris.
- Consult the pool equipment manuals and the product label prior to using any chemical.
Poor circulation will not only give a false reading but also mean chemicals do not spread through the water properly.
A safe method for raising alkalinity
It is best to proceed in an orderly fashion:
1. Make sure the pump is on and working normally. 2. Select a product made for adjusting pool alkalinity. 3. Read the label in full before you open it. 4. Put the product in exactly as the manual and label instruct. 5. Allow the water to circulate. 6. Do another test of the total alkalinity before doing anything else.
While some may reach for baking soda or a similar increaser, one should not guess at the dosage but instead put faith in the label and the pool’s manual. Under no circumstances should chemicals be mixed in a bucket or a container unless they are for pool use.
Proper application
For where and how to put in the chemicals, the equipment manual and product directions are your guide. Generally speaking, they should be put in a spot where the pool’s circulation can carry them around evenly and with safety.
Some basic precautions are worth observing: wear the right PPE like gloves and eye protection, keep pets and children at a distance, and wash up after handling the products. Store everything in a dry place with the seal intact. And if the skimmer basket needs attention, shut the pump off first. Never put a hand into suction equipment while it is running.
Pitfalls to avoid
There are a few common errors. These include putting in chemical before a test has been done, or treating the pool because the water appears off without an actual reading. Retesting too early, before the circulation has had its way, is another mistake, as is overlooking a clogged skimmer or low flow. Using the wrong chemical for the task is to be avoided. Hayward’s own maintenance advice is to stick to what the manufacturer says and to keep the skimmer and circulation in good shape.
Time to call in a pro?
If the total alkalinity continues to drop despite your efforts, or the pH is proving unmanageable, a qualified professional is the answer. The same goes for water that remains green or cloudy, or if there is an electrical fault, odd noise or a pump failure. If you are in doubt about which product to employ, or if the problem is mechanical rather than chemical, let a pro handle the diagnosis. It is far safer than trial and error. And if the water is unsafe or there are electrical issues, swimming is out of the question.
Sources and further reading
- [Hayward: Weekly pool maintenance](https://www.hayward.com/maintenance/weekly-pool-maintenance)