Review on capetsma 9-in-1 Aquarium Water Quality Testing Kit - pH, Nitrate, Nitrite, Carbonate, Hardness, Chlorine, Alkalinity, Iron, Copper - Ideal for Freshwater, Saltwater, Pool, and Pond Testing by Melissa Cook

I bought these test strips because they looked like a bargain but unfortunately they are useless. I have tested my reverse osmosis water and it was the only test that I can say is accurate, zero in all respects. Then I checked the tap water, the planted aquarium and the seawater aquarium. The planted tank had 20ppm nitrite on titration and the bar read zero. My saltwater aquarium was 5ppm when titrated and zero when using a strip. Out of frustration I made a strong solution of sodium nitrite and water just to see if I could get it to change color and it did, but both nitrate and nitrite turned the same color. The pH was also far from the same, ranging from 7.0 to 7.2 in the plant tank and 8.2 in the salt water tank, and both were the same color. Also, chlorine doesn't register in tap water, but it did when I added sodium nitrite in an experiment I conducted. Unsurprisingly, the carbonate hardness was also wrong. I would return them but I used up 1/3 of the box in experimentation and it's hardly worth it. I would not recommend these at all.