How does an API work and how it can help ports? What Are API Security Testing Tools? Akamai Answered Most Burning Questions About Web API Development Terminologies of Web Development GeeksforGeeks. Lowers pH in a freshwater aquarium Works fast Easy to use Is colourless; will not cloud or colour aquarium water Is phosphate free and nitrate free Will not encourage algae growth For fish to thrive, they need the water to be kept at the same pH level that they are accustomed to in nature When testing shows pH to be too high, use pH DOWN to lower it A pH of 6. 87. 2 is ideal for keeping an aquarium containing a variety of tropical fish