Lovibond

Lovibond pool water testing equipment and reagents

Pool water only behaves predictably when it is measured. Disinfectant level, pH, alkalinity, hardness and stabiliser all interact, and a reading taken with the wrong reagent or a dirty sample tube sends the whole dosing regime off course. Here you will find Lovibond test equipment for swimming pools and spas: visual comparators, handheld photometers, pocket meters, turbidity measurement, and the tablets, buffers and reference standards that keep them working.

From comparator discs to photometers

Two families of instrument cover most pool testing. The comparator uses a colour disc held against the sample: a tablet is crushed into the water, the colour develops, and the disc is turned until the shades match. The chlorine DPD comparator disc and the AF129K water balance comparator kit work this way, with no batteries and nothing to calibrate — useful as a plant-room backup or a second opinion.

Photometers read the same colour reaction electronically. The MD150 series is offered in several configurations, so the choice is driven by which parameters are actually needed:

• MD150 2-in-1 – chlorine and pH, the minimum for a chlorinated pool.
• MD150 3-in-1 – chlorine, pH and cyanuric acid, for outdoor pools using stabilised chlorine.
• MD150 6-in-1 – chlorine, pH, cyanuric acid, total alkalinity, calcium hardness and bromine, covering full water-balance work and spas on bromine.
• PM630 – a broader bench-style photometer for operators testing more parameters or more samples.

DPD tablets: which number does what

Chlorine testing relies on DPD reagent tablets, and the numbering matters. DPD No 1 develops colour with free chlorine — the fraction that is actively disinfecting. DPD No 3 is added afterwards to bring out total chlorine; the difference between the two readings is the combined chlorine, the chloramine load that causes odour and eye irritation. Both are stocked in 100-piece and 250-piece packs, so a busy commercial pool and a domestic owner can buy to their own consumption rate.

Tablets are moisture-sensitive. Keep the foil strips sealed until use, push the tablet straight from the foil into the sample rather than handling it, and replace stock that has discoloured. A tablet that will not crush cleanly or leaves an off-shade result is usually the cause when readings drift, not the instrument.

Pocket testers, turbidity and calibration

Electrode-based meters cover the parameters that colour chemistry cannot. The SD30 EC pocket tester reads TDS, salt and conductivity — the combination needed on salt-electrolysis pools, where the cell depends on the salt concentration staying inside its working window. The SD40 Multi adds pH to the same three, making it a single-pocket solution for routine checks. The TB211IR turbidity meter measures how much suspended material is clouding the water, which is the practical way to judge filtration performance before clarity is visible to the eye.

Instruments need supporting items to stay honest:

• pH 4 buffer solution – 0.15 litre bottle for calibrating pH electrodes; use fresh buffer and never pour used solution back.
• Reference standard kits – chlorine standards in separate versions for the PM630 and for the MD150, used to verify that a photometer still reads correctly.
• Pool water sampler – draws a sample from depth rather than the surface, where readings are least representative.
• Cleaning brush – for sample cells and vials; scratched or filmed glass scatters light and skews photometer results.

Choosing the right kit

Start from the sanitiser in use and the pool type. A stabilised outdoor pool needs cyanuric acid in the test set; a spa on bromine needs a bromine scale; a plastered or tiled pool benefits from calcium hardness and alkalinity for scale control. Then check consumables: whichever instrument is chosen, it will need the matching tablets or reagents indefinitely, so confirm that the pack sizes and reagent types suit the testing frequency before committing.

When ordering replacements, note the instrument model and the exact reagent description from the existing packaging. Tablet names such as DPD No 1 and DPD No 3 are not interchangeable, and reference standards are tied to a specific photometer.

Lovibond at PoolParthub.com

Here we list the Lovibond range used day to day on pools and spas: MD150 photometers in two, three and six parameter versions, the PM630, comparator discs and the AF129K water balance kit, SD30 and SD40 pocket testers, the TB211IR turbidity meter, and the samplers and brushes that support them.

Alongside the hardware sit the consumables — DPD No 1 and No 3 tablets in 100 and 250 piece packs, pH 4 buffer solution and chlorine reference standard kits — so that a meter bought today can still be fed and verified in a few seasons’ time.