Pool Alkalinity Increaser - Sodium Bicarbonate

Sodium bicarbonate alkalinity increaser for swimming pools. The clean, food-grade buffer that lifts total alkalinity 10 ppm per 15 g per m³ without disturbing pH.

• Raises total alkalinity approximately 10 ppm per 15 g per m³.
• Buffers pH so it stops bouncing between doses.
• Stops eye sting and corrosion that come with TA below 60 ppm.
• Lifts TA cleanly without adding calcium.
• Pairs with pH Plus when both pH and TA are low.

Sizes and prices

• 5kg: £24.00
• 10kg: £44.25
• 25kg: £105.00

When you need it

• Total alkalinity reads below 80 ppm.
• pH keeps drifting after correction; nothing is buffering it.
• Pool is freshly filled and TA is naturally low (15-30 ppm).
• Frequent acid dosing has stripped out the carbonate buffer.
• Eye sting persists even when pH is in band.

How to use

1. Test total alkalinity, pH and calcium hardness.
2. Calculate dose: 15 g per m³ raises TA by approximately 10 ppm.
3. Pre-dissolve dose in a 10 L bucket of pool water.
4. Pour solution slowly across the deep end with circulation on.
5. Run filtration 4 hours.
6. Retest TA and pH; pH may also lift slightly, recheck before re-dosing.

Dosing guide

Doses are starting points; retest 4 hours after dosing. Bicarbonate lifts pH slightly (around 0.05 per 15 g per m³); usually negligible but check before re-dosing pH chemicals.

• For 20 m³, add 300 g to reach Lift TA 10 ppm.
• For 40 m³, add 600 g to reach Lift TA 10 ppm.
• For 60 m³, add 900 g to reach Lift TA 10 ppm.
• For 40 m³, add 1.8 kg to reach Lift TA 30 ppm.
• For 100 m³, add 1.5 kg to reach Lift TA 10 ppm.

How it works

Sodium bicarbonate (NaHCO3) at 99% purity, food-grade baking soda, the standard total alkalinity buffer for swimming pools.

Bicarbonate ion provides the buffer reservoir that converts to carbonic acid when pH drops, and back to bicarbonate when pH lifts. Higher TA means a deeper reservoir; pH stays steadier.

Total alkalinity is the shock absorber for pH. Without it, every chlorine dose, every cal-hypo shock and every UV cycle moves pH. Get TA into the 80-120 ppm band and pH stays put.

Frequently asked questions

How much do I dose?

15 g per m³ raises TA by approximately 10 ppm. Always pre-dissolve and retest.

Will it raise pH too?

Slightly, around 0.05 per 15 g per m³. Usually negligible.

Why is alkalinity important?

TA buffers pH. Without it, every dose moves pH and you spend the season chasing the test reading.

Pack sizes?

5 kg, 10 kg and 25 kg sacks.

Is it the same as kitchen baking soda?

Yes. Pool-grade is the same compound at 99% purity, sold cheaper at sack scale.

How long does a pack last?

5 kg lasts a typical 40 m³ pool around 9-12 months.

What is the active ingredient?

Sodium bicarbonate (NaHCO3) at 99% purity.

How does it differ from soda ash?

Bicarbonate raises TA cleanly with minimal pH effect; soda ash raises both pH and TA together. Choose by which value needs lifting.

What TA range should I aim for?

80-120 ppm for plaster pools, 100-150 ppm for vinyl liner pools.

TA won't lift?

Test the dose accurately; freshly opened sack dissolves cleanly. Dump-doses cake on liner and waste product.

Cloudy after dose?

Pre-dissolve next time; cloud clears in 12 hours of filtration.

Bicarbonate vs soda ash?

Bicarbonate for TA only; soda ash for pH and TA together. Different jobs.

Bicarbonate vs sequestrant?

Bicarbonate buffers chemistry; sequestrant binds metals. Both can be dosed together if water is hard and metals are present.