I have two albino corys, one Julli cory and two emerald corys. They are in a 55 gallon with one pangasius cat, a pearl flowerhorn, a pleco, a banjo cat, and a spotted green puffer. Everyone gets along very well. The corys love to school together and you can tell the albinos are a pair - they are always together.
A pH of 7 is neutral. A pH less than 7 is acidic. A pH greater than 7 is basic. The pH scale is logarithmic and as a result, each whole pH value below 7 is ten times more acidic than the next higher value. For example, pH 4 is ten times more acidic than pH 5 and 100 times (10 times 10) more acidic than pH 6. The same holds true for pH values above 7, each of which is ten times more alkaline (another way to say basic) than the next lower whole value.
The strength of the acidity or alkalinity is expressed by the pH scale. Solutions with a pH of 7 are neutral. Solutions with a pH greater than 7 are alkaline. The higher the pH, the stronger the alkali. Solutions with a pH less than 7 are acidic. The lower the pH, the stronger the acid. If universal indicator is added to a solution it changes to a colour that shows the pH of the solution. Diagram of pH scale and universal indicator colours. Here are some examples of acids, alkalis and their pH values.