Review on Salifert OXPT Oxygen Test Kit by Thao Valdivieso

After 5 oxygen tests with this product the water was clear which means there is no oxygen in my pond. I have 2 large air pumps with working air stones. I have an Oase pump and a working filter. I have a fountain in my pond. Yes, there is oxygen in my pond. This test product is useless and does not work. I contacted the company that made this product and never got an answer as to why this test didn't work.