Overview of the LaMotte Insta-Test test strips – Phosphate (low range)
LaMotte low-range phosphate test strips measure the phosphate levels in a water sample. The pack include 25 test strips, a sample vial and a colour change chart (printed on the bottle). Within around 15 seconds, a colour change will develop in the sample vial; the user must then compare the colour change in the tube against the colour chart. Due to the need to estimate which colour the sample matches, this method is considered semi-quantitative.
Suitability for monitoring purposes
| Monitoring purpose category | Likely Tier(s) | Suitability |
| Engagement: Education and raising awareness | 0-1 | ✓ |
| Surveillance: Ecosystem health screening | 1 (2) | ? |
| Investigation: Helping to target further action | 2 (3) | ✖ |
| Evaluation: Assessing the impact of actions | 2 (3) | ✖ |
Details: Measures phosphate in the range 0 – 2500 ppb as PO4. Steps are 0, 100, 200, 300, 500, 1000 and 2500 ppb. Accuracy is not stated but assumed to be +/1 half a ‘step’.
Data System: N/A. Results are not stored on a device, so must be recorded and stored by the user.
Cost: VERY LOW. Around £7 inc. VAT per pack of 25 (c. £0.25/test).
Ease of use: EASY. Reagents are impregnated into each strip so users do not come into direct contact with them, and filling the sample vial with a 10mL syringe is easier (not provided).
Quality control: Local coordinators responsible for quality control. Measurement likely affected by extremes of temperature and turbidity so a good idea to measure and record those alongside the phosphate measurement if possible. Older strips can become unresponsive before the end of their shelf life.
Coverage / scale: Can be used anywhere – currently used by local / regional groups.
Health & safety: No known issues; users should not be touching the pad on the strips.