The organic matter from the leftover fish food and excretion of fish contaminates the water, and also causes the algae and germs inside the aquarium. COD is one of the indicators which tells the degree of water deterioration. When the aquarium is dirty or has too many fish inside, we see the high level of COD.
* Do NOT use for marine aquarium
|103-204||Pack Checker COD 5 packs|