pH Calculator
Calculate how much muriatic acid or soda ash to add to adjust your pool pH.
pH CALC
Current Water Chemistry
Quick-pick — auto-fills volume below.
Affects how much chemical is needed
6.0
7.0
7.4-7.6
8.0
8.5
7.2
Ideal Range
7.8
pH Adjustment
Chemical Needed
--
-- fl oz
Amount to add
Also equals
--
Will change pH to
--
Tip: Always add chemicals slowly with the pump running.
Wait 30 minutes, then retest before adding more.
pH naturally rises over time in most pools.
pH Chemicals Guide
To Lower pH (acid)
- Muriatic Acid (31.45%) - Most common, effective, cheapest
- Dry Acid (Sodium Bisulfate) - Easier to handle, more expensive
To Raise pH (base)
- Soda Ash (Sodium Carbonate) - Raises pH and TA together
- Borax - Raises pH with minimal TA impact
- Aeration - Free! Run returns/spillover to off-gas CO2
Safety: Always add acid to water, never water to acid.
Wear safety glasses and gloves when handling muriatic acid.
Add in front of a return jet for better distribution.
pH & Chlorine Effectiveness
Lower pH = more effective chlorine. Here's why 7.4-7.6 is ideal:
| pH | % HOCl (Active Chlorine) | Notes |
|---|---|---|
| 6.0 | 97% | Too acidic - damages equipment |
| 7.0 | 73% | Acceptable but low |
| 7.2 | 63% | Good |
| 7.4 | 52% | Ideal |
| 7.6 | 40% | Ideal |
| 7.8 | 30% | Acceptable but high |
| 8.0 | 21% | Too high - chlorine ineffective |
For educational purposes only — full disclaimer ↓