Total Alkalinity Increaser Sodium Bicarbonate

Steady your hot tub or pool water with pure sodium bicarbonate. By raising total alkalinity into the 80-120 ppm comfort band, it holds pH firmly between 7.2 and 7.6.

• Raises total alkalinity by roughly 10 ppm for every 17 g added per 1000 L.
• Provides the pH buffer that keeps daily drift in check.
• Has little direct effect on pH at normal doses.
• Cuts sanitiser consumption by ironing out pH spikes.
• Makes soaks more comfortable and stops the eye stinging soft water can cause.

Sizes and prices

Available in 1kg, 2.5kg, 5kg, 10kg, 20kg, 25kg.

• 1kg: £6.32
• 2.5kg: £12.14
• 5kg: £21.84
• 10kg: £41.24
• 20kg: £80.05
• 25kg: £99.45

How to use

1. Test total alkalinity, pH and calcium hardness with a fresh kit.
2. Work out the dose from the table, and never lift TA by more than 30 ppm in a single day.
3. Switch the circulation pump on and take out any floating dispenser.
4. Dissolve the dose in 5 L of warm tub water and stir it through.
5. Pour the solution slowly across the surface with the pump running.
6. Wait 4-6 hours, retest TA and pH, and only add more if TA is still under 80 ppm.

Frequently asked questions

What total alkalinity should I aim for?

80-120 ppm for chlorine hot tubs and pools, 80-100 ppm for bromine systems.

How much bicarb lifts TA by 10 ppm?

Around 17 g per 1000 L of water.

How long before I can bathe?

Give it 4-6 hours with the pump running, then retest pH and TA before you get in.

Is this just kitchen baking soda?

Chemically it is the same. Zagosa Spa & Pool supplies a 99%+ pool-grade bicarbonate that dissolves cleanly with no anti-caking agents.

How long does a 5 kg tub last?

Around 100-200 typical doses for a 1500 L hot tub, or a year of weekly maintenance on a 30 m3 pool.

Will it work in salt-water systems?

Yes. Salt chlorinators tend to push pH up, so you will use TA increaser less often than with tablets.

How does TA buffer pH?

Bicarbonate gives up or takes on protons depending on pH, so it soaks up the daily acid-base swings before they can move pH.

Does sodium bicarbonate raise pH?

Only marginally. Each 100 g per 1000 L lifts pH by about 0.05 units toward 8.3, its natural buffering point.

Does it raise total dissolved solids?

Yes. 100 g per 1000 L adds around 60 ppm TDS.

Why has TA spiked over 150 ppm?

Either you overdosed or your top-up water is high in carbonate. Bring it down with pH minus in 0.4-pH steps until TA is back in band.

Why is my pH rising even after dosing TA?

Heavy bicarbonate dosing slowly drives pH toward 8.3. Use smaller, more frequent doses for a smoother buffer.

Why is the water cloudy now?

Powder dosed neat alongside high calcium hardness can precipitate calcium carbonate. Filter for 24 hours and add a clarifier.

TA increaser or pH plus?

TA increaser (sodium bicarbonate) builds buffer with little pH change. pH plus (sodium carbonate) raises pH with little TA change.

TA increaser versus alkalinity-up tablets?

Both are bicarbonate. Powder dissolves faster and is easier to dose accurately than slow-release tablets.