Garra Gotyla Gotyla algae eating fish, also known as Tri-G fish, is ideal for combating the tough black beard algae. Until this fish species came along, this specific type of algae was difficult to remove from a tank. This type of fish relies on companionship so we suggest never having only one in a tank. At least two of the Tri-G fish in a tank is suggested. This fish is active and will have many periods of playfulness and rest throughout the day.