API Pond Pro Test Strips · 25 strips is a API-branded product in the ownkoi catalog. Five-in-one dry test strip from API: pH, alkalinity, carbonate hardness, nitrite, and nitrate. Each tube contains 25 strips. The manufacturer specifies that strips be read within 60 seconds of dipping. Specifications and pricing reflect the manufacturer-published or retailer-published data at the most recent catalog refresh. Verify the live listing on the source retailer page before purchase.