Stabilised Chlorine Granules SDIC

Stabilised chlorine granules that dissolve fast for instant top-ups and pH-neutral shocks. SDIC adds 1 ppm of free chlorine per 1.4 g per 1000 L and leaves pH where it is.

• Adds 1 ppm of free chlorine per 1.4 g per 1000 L.
• Dissolves fully in 60 seconds with no residue.
• Stays pH-neutral, so balance holds after dosing.
• Comes stabilised against UV burn-off with cyanuric acid built in.
• Suits daily top-ups, weekly shocks and post-fill chlorination.

Sizes and prices

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

• 1kg: £9.95
• 2.5kg: £17.62
• 5kg: £30.41
• 10kg: £55.98
• 20kg: £107.14
• 25kg: £132.71

How to use

1. Test free chlorine, pH and total alkalinity.
2. Confirm pH is 7.2-7.6 and alkalinity 80-120 ppm.
3. Dissolve the dose first in 5 L of warm tub water and stir it through.
4. Set the pump to circulation and pour the solution slowly across the surface.
5. Circulate for 30-60 minutes, then retest free chlorine.
6. Wait for free chlorine to drop below 5 ppm before bathing.

Frequently asked questions

How much SDIC lifts chlorine by 1 ppm?

1.4 g per 1000 L raises free chlorine by 1 ppm.

Is SDIC pH-neutral?

Yes. SDIC is the pH-neutral chlorine donor used the world over for daily dosing.

How long before I can bathe?

Wait for free chlorine to fall below 5 ppm, usually 60 minutes after a top-up.

How long does a 1 kg pack last?

Around 6-12 months of weekly maintenance for a 1500 L hot tub.

Will SDIC work in salt systems?

Yes. The granules back up salt chlorination during a heavy bather load.

Can I shock with SDIC?

Yes. Dose 5 ppm of free chlorine for a routine shock or 10 ppm for a heavy one.

What is the active ingredient?

Sodium dichloroisocyanurate dihydrate (SDIC) at >= 56% available chlorine.

Why does SDIC not affect pH?

The dichloro-cyanurate ion is balanced between acidic and basic groups, so pH stays in band as the granules dissolve.

Does SDIC raise stabiliser?

Yes. Each 10 ppm of free chlorine added by SDIC adds roughly 6 ppm of cyanuric acid.

Chlorine not climbing?

High combined chlorine; shock at 10 ppm and circulate for 4 hours.

Cloudy water after dosing?

The dose went in neat or pH is out of band; rebalance and clean the filter.

CYA too high?

Switch to calcium hypochlorite for shocks; refresh some water if CYA passes 80 ppm.

SDIC or TCCA tablets?

SDIC is fast-dissolving, pH-neutral granules for daily and shock dosing. TCCA is slow-release, acidic tablets for low-effort dispensing.

SDIC or calcium hypochlorite?

SDIC is stabilised and gentle on pH. Calcium hypochlorite is unstabilised, faster acting and raises pH; better for indoor pools and CYA-saturated water.