How to test phosphate-phosphorus (PO4-P) using the Kyoritsu packtest
What is it? Phosphorus is an element and a critical nutrient required by all life; the most common form is phosphate.
Why is it important? Phosphate plays a very important role as a nutrient in aquatic ecosystems. However, it is difficult to monitor due to its low concentration and its tendency to appear in both organic and inorganic forms. Often, water quality monitoring focuses on measuring total phosphorus rather than phosphate concentrations. While phosphorus is critical to all life, too many nutrients in the water can lead to water quality issues. High levels of phosphates can contribute to the formation of harmful algal blooms (HABs) and nuisance algae, such as Cladophora.
About the Kyoritsu test
How to test
- Take one tube out of the bag with the blue label (Phosphates). Pull out the plastic pin. Squeeze out the air from the tube.
- Holding the squeezed tube, put it into your sample and release to suck up the water (like a baster!). Your sample container should be half full.
- Invert at least 5 times to allow the reagent to dissolve in your sample. Set your timer for 5 minutes.
- Compare your results to the comparison chart. If the results are in between, record the halfway point.
Comparing results
Use the comparator provided with your kit and take your time. You're looking for whether values are low/medium/high, rather than precision (not possible with this type of test)! Do not compare with a screenshot or photograph, as lighting will make it inaccurate.
Interpreting results
Normal levels depend on your location. The following values apply to the UK:
- 0 - 0.02 ppm: Low/Normal
- 0.02 - 0.1 ppm: Medium
- 0.2 - 0.5 ppm: High
- 0.5 - 1 ppm: Very high
Watch the protocol in action