New Filter, fish struggling

[Capnyeehaw]

Hello,
This is my first time posting so I hope this is the right place. So i have had a betta for a few months, and everything has been going okay, but this morning when I put a new filter cartridge in (I have a tetra whisper internal cartridge filter if that’s relevant), he hasn’t left the top of the tank. He goes to the top and stops moving, which is very abnormal and I would like some advice on what I should do.

Thanks for any responses

 

[PheonixKingZ]

Picture, of filter please. What specific kind of betta do you have?

 

[FishFinatic77]

It could be that you don't have enough good bacteria in your tank anymore because you exchanged the cartridge.
Do you have a test kit? If you don't, bring your water to your nearest pet store. They should be able to test your water for you.
If your water parameters are bad, take some water out of the tank and exchange it with new water. Don't vacuum the gravel as this will get rid of even more bacteria.
When you change your cartridge, you should put the old one behind the new one and leave it like that for a few days. This will allow bacteria to grow on the new cartridge, avoiding any problems.
Good luck!

 

[Guppylover3x]

This thread is a double post.

 

[FishGuest5123]

It could be that you don't have enough good bacteria in your tank anymore because you exchanged the cartridge.
Do you have a test kit? If you don't, bring your water to your nearest pet store. They should be able to test your water for you.
If your water parameters are bad, take some water out of the tank and exchange it with new water. Don't vacuum the gravel as this will get rid of even more bacteria.
When you change your cartridge, you should put the old one behind the new one and leave it like that for a few days. This will allow bacteria to grow on the new cartridge, avoiding any problems.
Good luck!

Excellent response and advice!

 

[Guppylover3x]

I agree with @Deanasue very informative advice.

Good job