5 Gallon Betta Tank With A 10-20 Gallon Filter

[Kipsie]

We got a new tank (my 10 gallon was leaking), and filter and heater for my betta.
But the filter I got was for 10-20 gallon.
Do you think he'll be okay? He swims oddly and jerky but i'm wondering if I can turn it on and off for his sake or must it stay on 24/7?

 

[OldMan47]

You have two choices with a filter. You can run it 7/24 and consider the tank a filtered tank or run it a mere 20 or less hours per day and consider it an unfiltered tank. Do not kid yourself that you have a filtered tank but only run the filter part time.
An unfiltered tank is maintained by doing massive and frequent water changes. There is no flexibility about maintenance regimes on an unfiltered tank because the water quality can and will go bad in a hurry if you miss even one water change.
Your short picture of your betta swimming around your waterfall led me to think he was playing in the water flow, not suffering from it.

 

[Kipsie]

Oh, I thought it was a possibility he liked it, too.
Okay, thank-you, it's staying on.

You are all so helpful!