betta getting sucked in by filter

[fishforum213]

hi there
yesterday i bought a male betta fish to go in my 5.5 gallon tank - he seemed happy enough yesterday but today i came home to him stuck next to the filter. He was fine as soon as I turned the filter off but his fine look slightly tattered and i’m nervous to turn it back on. My first thought was to buy him a weaker filter but this one is not particularly strong and it’s a sponge filter - when i looked online it said even bettas should be fine with it. i was wondering if i keep it on will he build up the muscle to be able to swim against it or do i need to somehow find a weaker one? And if I do, will he be okay overnight without the filter on? (sorry if i’m asking obvious questions he’s my first fish). thank you

 

[fishforum213]

also do i have to turn the heater off if there’s no filter and will he be okay with that?

 

[JuiceBox52]

Try reducing the airflow to the sponge filter