CrystaLux pH Minus 7kg Pool & Spa pH Reducer
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Pull pH back into the safe zone, fast.
CrystaLux pH Reducer is dry-acid sodium bisulphate granules that bring pool and spa pH back down into the 7.2 to 7.6 target range. High pH causes cloudy water, scale on tiles and fittings, and a sluggish chlorine. A measured dose, properly distributed, fixes it within hours.
How to Use
1. Test pH and total alkalinity before dosing. Target pH is 7.2 to 7.6. Typical total alkalinity target is 80 to 120 ppm. 2. Pre-dissolve granules in a clean bucket of pool water. 3. Add slowly with the pump running, distributed around the perimeter for general pH correction. 4. Wait 4 to 6 hours, retest, and dose again only if needed.
Routine pH correction: dose gradually according to your test result and pool volume. High total alkalinity correction: use smaller repeated doses, retest between applications, and avoid driving pH too low. Aeration can help raise pH again without adding alkalinity. Always retest before re-dosing. Do not add large doses in one hit.
FAQ
Why is my pH always high?
High pH commonly comes from new plaster pools curing, hard fill water, frequent splash-out and top-ups, or aerators and water features off-gassing CO2. The fix is regular pH Reducer dosing, ideally with weekly testing.
How is this different from muriatic acid?
Sodium bisulphate is dry granular acid, easier and safer to store and dose than liquid muriatic (hydrochloric) acid. It is the standard for residential pool care in the UK.
Can I use this with my salt chlorinator?
Yes. Salt pools tend to drift to higher pH because the cell off-gases CO2; pH Reducer is a frequent need for salt chlorinator owners.
Will it lower alkalinity too?
Yes, it lowers both pH and alkalinity. If alkalinity is in range and only pH is high, dose conservatively to avoid pulling alkalinity below 80 ppm.
How long will 7kg last?
For a typical 50,000L UK pool with seasonal use, a 7 kg pack covers approximately one full season of routine pH corrections.
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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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.
Our Full Range
Your One Stop Place for All the Pool & Hot Tub Water Treatment