Hach teststrips (nitrites)
Hach nitrite teststrips are an easy way to check for nitrites (a type of nutrient) in water.
To use them, dip a teststrip into your water sample for a few seconds, then remove it and wait about 1 minute. The strip will change colour based on how much nitrite is in the water.
Compare the colour on the strip to the chart provided on the bottle or packaging. Each colour matches a specific nitrite level, shown in mg/L.