Help! Betta acting strange!

[Hybridfish7]

I have a koi halfmoon betta in a 2.5 gallon tank. I've had him for about 4 months now, and only recently moved him into this tank. Well for one the flow of the tank is pretty strong. Any suggestions on slowing the flow? The intake of the filter also seems to be pretty strong... I just turned it off so he can relax a bit. Other than the filter, he just randomly flares and twitches, and occasionally scratches his right side on the piece of wood I have in there. I looked at him from every angle... No parasites or anything on him, just a small gash from scratching up against the wood.

 

[tlindsey]

I have a koi halfmoon betta in a 2.5 gallon tank. I've had him for about 4 months now, and only recently moved him into this tank. Well for one the flow of the tank is pretty strong. Any suggestions on slowing the flow? The intake of the filter also seems to be pretty strong... I just turned it off so he can relax a bit. Other than the filter, he just randomly flares and twitches, and occasionally scratches his right side on the piece of wood I have in there. I looked at him from every angle... No parasites or anything on him, just a small gash from scratching up against the wood.

The Betta will get stressed out if it's fighting to swim in to strong of current. Also what type of filter is it?

 

[Hybridfish7]

It's one of those filters that are built into the back of a tank...

this is the tank
When I first got it the flow didn't look to be too strong
and when I first put him in he was able to swim just fine
Only if he swam directly in front of the output he'd get pushed a bit
now he just hides under the plants and yesterday he was doing all that scratching and twitching...

 

[J. H.]

If you stuff a sponge in the hob, or wrap the intake with a piece of stockings, you can greatly reduce the flow and increase your bio, if that's a bonus you care about.