is my fish behaving strangely?

[FinFan]

I've had my betta for about a week now. At first, he was all about exploring his new tank. But for the past few days, I've noticed him swimming back and forth at the back of the tank a lot.

I thought maybe he was seeing his reflection or something, so I covered half the tank with a towel to see if that'd change anything. It didn't seem to make a difference, though. He does take breaks every now and then, but he always ends up going back to that same back-and-forth pattern. No flaring or anything, just pacing.

He looks healthy, though - he swims up to greet me whenever I walk into the room, and he's eating really well. I did just move him from a small bowl to a 5-gallon tank, so maybe he's just adjusting to the new space?

I'm also wondering if the filter might be too strong. It's on its lowest setting, and I've got it pointed at the wall to slow down the flow. He doesn't seem to have any trouble swimming, though. Any thoughts on this would be great, thanks.

[SeaBidder]

Have you checked your tank parameters to make sure everything is okay? I'm thinking he might be a bit bored, to be honest. Adding a bright colored toy, like a ping pong ball, could give him something to play with and break the monotony of swimming back and forth.

[lunarix]

I'd recommend getting some albino tetras or cherry barbs. They're pretty fast, so your betta will likely chase them thinking they're enemies, but they'll be too quick for him. Just make sure to get a healthy and happy one.

[sSjey]

Introducing fish solely for the purpose of being chased is, in my opinion, a form of cruelty. It's extremely stressful for fish to live in constant fear of another fish.

Buying a single tetra is also inhumane, considering tetras are naturally shoaling fish that thrive in the company of their own kind.