Originally Posted by nemo number2
I'm no expert, but:
Put a small pump in there to keep the water oxygenated.
The plant could be competing with the fish so that may not be helping.
Try a silk one.
styrofoam may not be the best either.
Actually, bettas are labyrinth fish, meaning essentially that they can take atmospheric oxygen directly from the air. They do not require additional aeration from a bubbler to breathe. Live plants also do not take air from them...
Martylaroche5, does your tank have a heater? Is there anyway for you to tell exactly what the temperature is? The ideal temperature for bettas is roughly between 78-82 degrees Fahrenheit (approximately 25-27 degrees Celsius) and too cold water might cause bettas to be sluggish and inactive.
Is your betta fish's long finned? You mentioned a filter. How strong is the water flow from it? The current from the water filter may also be too strong for some bettas and give them trouble when they are swimming.
Swimming sideways could also be due to swim bladder disorder (SDB), which can be something he is prone to because of genetics or caused by overfeeding and/or stress.
A little more information might help us figure out what is wrong with your betta.