Phenol Red Test Tablets - 250 Tablets

Palintest Phenol Red reagent tablets, boxed in 250s, for reading pH on a comparator or photometer. A rapid-dissolve tablet develops a colour that maps to a measured pH figure across the pool and spa range, so you set balance from a number rather than a strip guess. Pair with DPD tablets for the chlorine side.

• Reads pH as a measured figure on a comparator or photometer.
• Covers the working pH band used for spa, hot tub and pool water.
• Dissolves fast in the sample cell for a clean, even colour.
• Gives repeatable pH readings that dip strips cannot match.
• Sits alongside DPD tablets so one kit handles pH and chlorine.

Price

£24.95

How to use

1. Rinse the test cell with the water you are about to test.
2. Fill the cell to the 10 ml line with a fresh sample.
3. Drop in one Phenol Red tablet without touching it.
4. Crush and mix until the tablet has fully dissolved.
5. Read the pH on the comparator disc or photometer straight away.
6. Log the pH and dose acid or pH plus if it is out of band.

Frequently asked questions

What does Phenol Red measure?

pH. The tablet develops a colour that maps to a pH figure across the working spa and pool range.

Is this a dip strip?

No. Phenol Red tablets are for comparator or photometer testing, giving a measured pH rather than a strip colour band.

How many tablets in a box?

250 tablets, so 250 pH tests.

What handles chlorine?

DPD No 1 tablets for free chlorine and DPD No 3 for total. Phenol Red is the pH half of the same kit.

Can I run pH and chlorine together?

Yes. Use a Phenol Red tablet for pH and DPD tablets for chlorine on the same comparator or photometer.

Why does high chlorine affect it?

Strong sanitiser can bleach the Phenol Red colour, so read promptly or dilute a very high-sanitiser sample first.

Why does pH matter so much?

pH steers sanitiser efficiency and bather comfort, so an accurate figure keeps both in check.

Tablets or strips for pH?

Tablets on an instrument give a measured, repeatable pH; strips only give an approximate colour band.

What sample volume?

One tablet per 10 ml sample in the test cell.

Colour washed out?

Sanitiser has bleached the indicator; read fast, or dilute a very high sample and retest.

pH off the top?

It is over range; dose pH reducer, circulate and retest.