





CrystaLux Multifunctional Chlorine Tablets 20g Hot Tub & Small Pool 5kg
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4 jobs in 1 tablet. Cleaner water, less faffing.
CrystaLux Multifunctional Chlorine Tablets are slow-dissolving 20g pucks formulated for hot tubs and smaller pools. Each tablet sanitises, controls algae, clarifies water, softens the feel, and stabilises against UV loss. Drop into a floating dispenser or skimmer basket and let it work for days.
How to Use
1. Test your water. Target free chlorine 3 to 5 ppm in spas, 1 to 3 ppm in pools, pH 7.2 to 7.6.
2. Place tablets in a floating dispenser, skimmer basket, or in-line feeder. Never drop directly into the pool or spa.
3. Start with 1 tablet per 1,000 litres of water in spas, 1 tablet per 2,000 litres in pools.
4. Retest every 2 to 3 days and adjust dispenser opening to maintain target level.
Important Tablet Size Guidance
These are small 20g multifunctional chlorine tablets, designed for hot tubs, spas, inflatable pools, above-ground pools, and smaller swimming pools.
Each 20g tablet is intended for smaller water volumes, offering easier and more controlled dosing than large 200g tablets.
For larger swimming pools, especially pools above approx. 10,000 gallons / 45,000 litres, we recommend using 200g chlorine tablets instead, as they are longer-lasting and more practical for higher water volumes.
Please check your pool or spa water volume before ordering.
FAQ
Why a 20g tablet instead of 200g?
20g tablets dissolve over a few days and dose more accurately for smaller bodies of water like hot tubs and pools up to 20,000L. 200g tablets are designed for larger pools where one tablet can sanitise 50,000L for up to a week.
Can I drop a tablet straight into my hot tub?
No. Always use a floating dispenser, skimmer, or in-line feeder. Direct contact with surfaces can bleach hot tub liners or pool finishes and create dangerously high local chlorine concentrations.
Will these lower my pH?
Continued use of TCCA-based tablets gradually drops pH because the active substance is mildly acidic in solution. We recommend stocking pH Increaser to keep your reading in the 7.2 to 7.6 target range.
How long does one tablet last?
In a 1,500L hot tub, a 20g tablet typically lasts 3 to 5 days depending on water temperature, bather load, and dispenser flow setting. In a small pool, expect 5 to 7 days.
Can I mix 20g and 200g tablets?
Yes, but only in separate dispensers or feeders, never in the same one. The dissolve rate differs and mixing can cause uneven sanitisation.
Shipping & Returns
You can return seal unused product back to us within 14 days from the purchase for a full refund. Buyer is resporesponsible for the postage. Learn more about our shipping policy.
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Your One Stop Place for All the Pool & Hot Tub Water Treatment
The CrystaLux Standard
CrystaLux was created for people who believe clear water should feel effortless.
Your pool or hot tub is more than water in a shell. It is where summer slows down, where weekends begin, where guests gather, and where your home feels just a little more special. That experience deserves products that feel as considered as the space itself.
That is why CrystaLux takes everyday pool care and makes it cleaner, simpler, and more refined. No confusing jargon. No messy guesswork. Just premium water-care essentials with clear instructions, practical dosing, and a design that looks as good as the water you are working towards.
Every CrystaLux product is part of the same promise: confident care, clearer water, and a pool routine that feels under control.
Because when the water looks right, everything around it feels better.
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