Hello everyone, I wanted to know how often do you do a water change and how much do you change out in your thanks. I have a 75 gallon tank with a fluval fx4 running in it. Currently I have 13 cichlids in it and 1 clown loach which are all about 2 inches long. Also if anyone has any tips on how to properly add water back into the tank. The water from my tap doesnt have a high enough PH so I'm not sure if I should fill up buckets with water and then use API PH up or can I add the water directly to the tank and then add the PH up. I was advised to add crushed coral to my tank to help maintain the PH but I'm not sure if that is enough to keep the PH in a healthy range.