May I make a suggestion, From the picture, and from what you said, your tank is 24 inches tall, and it looks like you have one powerhead, and a hang on the back filter. From the picture both are located very high in the tank. Look to be in the top 1/4 of the tank. So it doesn't seen like your water in the bottom half of your tank is not going to get circulated properly. That will cause big problems down the road. You need to get one or two more powerheads and put them low in the tank and have them blow at an upward angle. Not straigt up. But you need to get the water from the bottom of your tank to the top so if can get properly filtered also.