Betta fish acrobatics

Question
Hello Jaymie about a month ago I set up a 5 gallon tank with some live plants, a snail and one male plakat. My betta fish chases his reflection around the tank almost non stop, face pushed right into the glass with only occasional breaks for air. From research on bettas I have read that they are relatively slow moving fish. However my betta will chase his reflection very swiftly, sometimes violently rocketing from one end of the tank to the other or from the very top down into the gravel. This is the only thing he does all day. Trying to break him of his habit I kept the tank in complete darkness for 3 days, but the second I uncovered it, he was back at it. I know that defending his territory is natural, but he's not flaring and seems otherwise healthy. Should I stop worrying?

Answer
Benjamin,
The longer the tails and fins, the slower it swims, but most can swim quite quickly. The best way to stop him from that behavior is to cover the tank. At the pet stores, they have rolls of decorative backgrounds. Measure from the front of one side to the other. This means it will cover all but the front of the tank. This should help with this. It might not stop him completely, but it should slow it down a bit.