Phosphorus and Phosphate Detection Test Strips, 0-100 ppm [Vial of 50 Strips]
Brand: Bartovation

The Phosphate test strip detects orthophosphate ions and expresses the result as ppm phosphorus. To express the result as phosphate, multiply the result by 3. This test strip has a unique construction for more accurate testing. This strip has a detection limit of 5PPM phosphorus, and can NOT be used to detect anything below that. Instructions: Dip the test strip into the solution to be tested for 1 second. Remove and compare against the color chart after 3 minutes.
This strip cannot detect triphosphates. Tripolyphosphates must be converted to orthophosphate first to be detected.
Remember that the Phosphate test strip gives ppm as Phosphate, not phosphate ion. The result should be corrected for any dilutions/additions and multiplied by 3 to arrive at the phosphate ion ppm.
There are some interferences to consider:
Arsenate and silicates above 20 ppm will cause a false reaction. These will form a yellow color.
Fluoride, chlorides, and nitrites above 50 ppm will depress the phosphate reaction on the strips.
Heavy metals will depress the result.
Large quantities of oxidizing compounds will also depress the result.
Lastly, pH and temperature will affect the results. The pH of the sample should be in the range of 6-9.
For temperature, the best results are obtained in the range of 18-30 C. Above or below this the reaction on the strip can be depressed.

No reagents or field kits needed for tests, all you need is one strip and no chemicals
Easy to use waterproof color chart printed on every vial along with instrucions
Distinct color scale with marks at 0, 30, 75, 150, and 300 PPM Phosphate (and 0, 10, 25, 50, and 100 PPM Phosphorus)
Long plastic strips ensure you can keep your fingers away from what is being tested
This strip has a detection limit of 5PPM Phosphorus, and can NOT be used to detect anything below that