The Ruby Cardinal is commonly referred to as the Red Stop Light Cardinal. The Ruby Cardinal makes a beautiful fish in any tank, with its bold color and pattern, it makes a striking fish. The Ruby Cardinal thrives well in a temperature range of 72-78 degrees Fahrenheit and pH of 8.1-8.4. The Ruby Cardinal is very easy to care for and makes a great fish for a beginner aquarist. The Ruby Cardinal grows up to 3 inches and needs to be kept in a tank not less than 30 gallons. The Ruby Cardinal is carnivores in nature and needs to be fed with meaty foods as shrimps and vitamin enriched food. It requires a tank with plenty of caves and coral heads to hide, which also makes an idle environment for this fish to flourish. The Ruby Cardinal does well in small groups and makes a great reef tank species. The Ruby Cardinal is considered very safe for reefs, and can be kept safely in any reef tank. Make sure to incorporate many plants in the tank in which the Ruby Cardinal can hide whenever it needs.