Phosphates

Here’s a short review of various commonly used methods for testing phosphates (sometimes called phosphate-phosphorus!).

  • Hanna checkers
  • Kyoritsu packtest
  • Lamotte test strips

Hanna checker (phosphates – low range)

Test nameHanna checker (phosphates – low range)Tips
Test typePowder reagent in liquidProviding small scissors allows volunteers to open reagent safely
Range0 – 2.5ppmThere is also a high range version used by hot spots.
Accuracy★★★★★Gives a result numerically with a value. See below for comparison research
Ease of use★★★Requires training
Safety/disposal★★Liquid Requires training
Maintenance★★Providing small scissors allows volunteers to open reagent safely. Requires cleaning and calibration
Availability★★★★Easily available for purchase.
CostUpfront: ££, per test: £

Used by: Thames21, Norfolk Rivers Trust, and South East Rivers Trust.

Guidance for use: Great for small groups of well-trained volunteers doing consistent monitoring who are able to calibrate and clean meters appropriately. Provides more precision for when low/medium/high are not sufficient. Less ideal for large groups where direct oversight for training is not possible.

Guides and resources: links to resources coming soon!

Research: links to research coming soon!

Reviewed by XX groups (see individual reviews coming soon)

Kyoritsu Packtest (phosphate-phosphorus – low range)

Test nameKyoritsu Packtest (phosphate-phosphorus – low range)Top tip
Test typePre-filled powder reagent in liquidPracticing this test builds confidence.
Range0 – 1 ppmNote: units are equivalent to 0 – 2ppm of phosphates. There is also a high range version that can be used in hot spots.
Accuracy★★★Colour comparison method. Great for knowing if values are low/medium/high.
Ease of use★★★★Requires some training but easy enough to send out to large groups.
Safety/disposal★★★★Reagent is contained in the tube. Liquid down the sink and
Maintenance★★★★No maintenance required. Watch for expiration dates.
Availability★★★Through programs and intermediaries
CostUpfront: nil, per test: ££

Used by: many groups through FreshwaterWatch UK, Water Rangers UK.

Guidance for use: Good for large groups and understanding when readings are low/medium/high. Used often for blitz events over hundreds of sample locations.

Guides and resources:

Research: coming soon!

Reviews by Water Rangers (see individual reviews coming soon)

LaMotte test strips – phosphate low-range

Test nameLamotte phosphate teststripsTop tip
Test typeTest stripsEmphasize keeping test strips dry!
Range0 – 2,500 ppbNote: units are equivalent to 0 – 2.5ppm of phosphates. There is also a high range version that can be used in hot spots.
Accuracy★★★Colour comparison method. Great for knowing if values are low/medium/high.
Ease of use★★★★Requires some training but easy enough to send out to large groups.
Safety/disposal★★★★Used liquid goes donw the normal sink. Can be disposed of in the normal waste system.
Maintenance★★★Tube must be cleaned appropriately. Watch for expiration dates.
Availability★★★★Available online in a few places.
CostUpfront: nil, per test: £

Used by: Westcountry CSI.

Guidance for use: Excellent for large groups (e.g. Westcountry maintains 500 active testers) and for understanding when readings are low/medium/high. Used often for blitz events over hundreds of sample locations.

Guides and resources: Westcountry CSI’s manual

Research: coming soon!

Reviews by XX groups (see individual reviews coming soon)

Do you know another phosphate test that is used and researched by a local group? Let us know!

Updated on May 1, 2024