Description
Non-chlorine shock (MPS, or potassium monopersulfate) is the go-to oxidiser for hot tub and spa owners who want to clear bather waste and restore water clarity without raising chlorine levels, and it is also the standard shock partner for chlorine-free and mineral sanitising systems. Standard chlorine strips cannot read it. These Deep Blue MPS 3-in-1 test strips measure the active MPS level alongside pH and total alkalinity, so you can confirm your shock dose has done its job and your water balance is right for it to work.
Testing takes seconds: dip the strip for five seconds with a gentle back-and-forth motion, shake once, wait 15 seconds and match the three pads to the colour chart printed on the tube. Reading pH first, then MPS, then total alkalinity keeps the result accurate, and OK, LOW and HIGH ranges on the chart make interpretation immediate.
Deep Blue water testing products are manufactured to a high standard and colour-matched for accurate, repeatable readings, and our test strip range is trusted by pool professionals, holiday let operators and serious home users across the UK.
The strips are calibrated at 38°C (100°F), the typical hot tub operating temperature. Note that pH may read low if total alkalinity is below 80ppm, so correct alkalinity first and retest. Keep the tube tightly capped and dry between uses.
How to Use
- Dip one strip in the water for 5 seconds with a gentle back and forth motion.
- Remove the strip and shake once, briskly, to remove excess water.
- Wait 15 seconds.
- Match pH, MPS and total alkalinity, in this order, to the colour chart. Complete colour matching within 30 seconds.








Florence A. Baker –
Very good good quality. Very pleased. Would reorder.
Ms Zachary Harper –
Swim. works well pleased overall. Happy with it. Pleased overall.
Miss Carter Green-Doyle –
Pleased overall great finish exactly as described.
Ms Aria Martin –
Excellent good for the money and happy overall. Would buy again.
Teddy Walsh –
Good feels robust works as intended. Would reorder.
Alfie X. Jones –
Good value for money, excellent communication and speedy delivery.
Mr Saad X. Pearson –
Satisfied customer
Molly Reynolds –
Delivery as expected thanks works well pleased overall. ref 91
I. W. Walsh –
Highly pleased reliable performance exactly as described.
Jaspreet Hawkins –
First I thought it was a scam with prices so low Would recommend. ref 79
Victoria U. Harrison –
Work great
Mr Paige McDonald –
Good no fuss to use. As expected. No hassles. Will use again.
Emma Z. Hawkins –
What a super product works well pleased overall. Would buy again.
Miss R. A. Hughes –
Decent test with dependable quality simple to apply, good enough.
Sunil Turner –
Beautiful product works well pleased overall. Would recommend.
Sophia Mahmood –
Fair very effective and does what I needed. All as described.
Sajid M. Pearson –
Good value for money, excellent communication and speedy delivery. works well pleased ref 76
Mr Sam S. Robertson –
Top quality really works, great value happy with it.
X. M. Harper –
Very happy, clear, accurate readings with gentle, steady sanitising, reliable treatment.
Damian Q. Mitchell-Taylor –
First I thought it was a scam with prices so low Would recommend.
Dr Seamus Fleming –
Fantastic good for the money and great results. Arrived quickly.
Finlay Sinclair –
Very impressed does exactly what s needed and happy overall.
Dr Dev Bishop –
Excellent good for the money. Does what it says.
Aaron Evans –
Excellent fairly priced works as intended. Arrived quickly.
Miss Sophia Taylor –
Grand
Sajid Walsh –
Just great
Ruby Kennedy –
Good good for the money does what it says. Would buy again.
Skye Robertson –
Just great nicely made does what I needed. Good experience overall.
Kai R. Sinclair –
Great product and worked well. Great value for money works well pleased
Mrs Eleanor Fraser –
Delivery as expected thanks works well pleased overall. ref 81
Mr Murdo D. Singh –
Brilliant quick to set up. Solid outcome. Good value.
Mairi Harper –
Top quality, clear, accurate readings pro grade performance. Would buy again.
I. Clark –
Tablets. works well pleased overall. Would recommend.
C. Hill –
Wonderful very effective and meets expectations.
Miss Jessica W. Brar –
Great buy, pro grade performance clear, accurate readings effective on tough jobs. Does the job.
Hamish Cox –
Packed well, bromine in perfect condition.
Mrs Victoria R. Bhat –
Easy to use and good value works well pleased ref 78
Miss Tamsin Cox –
Solid product, gentle, steady sanitising pro grade performance. Will reorder.
Amber O. Williams –
Impressed chlorine with good performance did the job, would buy again.
Ms X. Cox –
Pretty decent test with consistent performance performed consistently, works okay.