Domakihub How to lower the pH in your pool
High pH makes chlorine lazy, clouds the water and scales your tiles. Here's how to bring it back into range safely.
Reviewed by Domakihub pool pros · 2026-06-23 · 4 min read
When pool pH drifts above 7.6, your chlorine stops working properly, the water goes cloudy and scale builds on tiles and equipment. Lowering it is simple chemistry done in the right order. The video above explains why; the steps below are the safe way to do it.
What your pH should be
Aim for 7.2–7.6. In that range chlorine sanitises efficiently and the water is comfortable on skin and eyes.
Check total alkalinity too (80–120 ppm): it acts as a buffer, and lowering pH usually lowers alkalinity a little as well.
What you'll need
A reliable test kit and a pH reducer — either dry acid (sodium bisulfate, easier and safer to handle) or muriatic acid (the pro standard). Wear gloves and eye protection and never mix the two.
Lower your pool pH in 5 steps
- 1
Test pH and alkalinity
Get an accurate reading first. Only act if pH is above ~7.6 — overshooting low pH is corrosive.
- 2
Choose your acid
Dry acid (pH Down) is granular and beginner-friendly; muriatic acid is liquid, cheaper and faster but needs careful handling.
- 3
Calculate the dose
Use the product's chart for your pool volume and how far pH needs to drop. Add less than you think — you can always add more.
- 4
Add it with the pump running
Pour slowly into the deep end (or a flowing return) with the pump on so it disperses. Never add acid near skimmers or to a still pool.
- 5
Wait, then re-test
Let it circulate for 4–6 hours, then re-test. Adjust again if needed and re-check alkalinity before swimming.
Rather have a pro handle it?
Get a vetted pool pro in your city — one number, booked in EN/EL/DE.
FAQ
- What raises pool pH in the first place?
- Fresh fill water, high alkalinity, a new plaster surface, and adding chlorine like cal-hypo or liquid bleach all push pH up over time.
- Dry acid or muriatic acid — which should I use?
- For a home pool, dry acid is safer and easier to dose. Muriatic acid is cheaper per use and preferred by pros, but it's a strong liquid acid — handle with care.
- Can I swim right after lowering pH?
- Wait until it has circulated and you've re-tested into the 7.2–7.6 range, usually a few hours after dosing.