Maintaining a clean and safe swimming pool requires an effective disinfectant. TCCA 90% tablets (Trichloroisocyanuric Acid, CAS 87-90-1) are one of the most popular choices for pool owners and operators due to their high available chlorine content (up to 90%) and slow-dissolving nature. This guide will walk you through how to use TCCA 90% tablets correctly for optimal pool disinfection.
Why Choose TCCA 90% Tablets for Your Pool?
High Efficiency: Contains 90% available chlorine, killing bacteria, viruses, and algae quickly.
Stable Release: Tablets dissolve slowly, providing long-lasting disinfection (typically 5–7 days per tablet in a feeder).
Convenient Storage: More stable than liquid chlorine or bleaching powder.
Cyanuric Acid (CYA) Stabilizer: TCCA releases cyanuric acid, which protects chlorine from UV degradation, making it ideal for outdoor pools.
Equipment You'll Need:
TCCA 90% tablets (200g, 100g, or smaller sizes)
A floating chlorinator or an inline feeder
Test kit for chlorine and pH levels
Protective gloves and goggles
Step-by-Step Usage Guide
Step 1: Test Your Pool Water
Before adding any chemicals, test the current chlorine level and pH. Ideal ranges:
Free chlorine: 1–3 ppm (parts per million)
pH: 7.2–7.6
Step 2: Calculate the Correct Dosage
As a general rule for TCCA 90% tablets:
For every 10,000 gallons (approx. 37,854 liters) of pool water, use one 200g tablet per week.
Adjust based on pool usage, temperature, and sunlight exposure.
| Pool Size (Gallons) | TCCA 200g Tablets per Week | Chlorine Level Expected |
| Up to 10,000 | 1 tablet | 1-3 ppm |
| 10,000 – 20,000 | 2 tablets | 1-3 ppm |
| 20,000 – 30,000 | 3 tablets | 1-3 ppm |
Step 3: Add Tablets to the Feeder
Floating chlorinator: Open the device, place the required number of tablets, adjust the flow dial (start at a medium setting), and let it float in the pool.
Inline feeder (for in-ground pools): Turn off the pump, open the feeder canister, add tablets, close tightly, and restart the pump.
Step 4: Run the Pump
Allow the pool pump to run for at least 4–6 hours to circulate the dissolved TCCA evenly.
Step 5: Retest and Adjust
After 24 hours, retest the free chlorine level. If it is below 1 ppm, add half a tablet; if above 3 ppm, remove some tablets or lower the feeder setting.
Safety Precautions
Never mix TCCA with other chemicals (especially acids or ammonia-based cleaners) – toxic chlorine gas can be released.
Store in a cool, dry place away from direct sunlight and moisture.
Use gloves and goggles when handling tablets.
Keep out of reach of children.