Fish swimming near the top of the tank

[Mollyrosebruton]

Hello,

About 2 months ago I started a tropical tank, I bought some guppies and danios to start off with and they have been absolutely fine. I have just put two dwarf gourami’s in the tank and now the danios and guppies are staying right at the top of the tank at the waters surface. Is there a reason why they’d do this?

Thanks
Molly

 

[Colin_T]

Any chance of a short 30-60 second video of the fish?
If the video is too big for this website, post it on YouTube and copy & paste the link here. We can view it at YouTube. If you are using a mobile phone to take the video, have the phone horizontal so the video takes up the entire screen. If you have the phone vertical, you get video in the middle and black on either side.

Test the ammonia, nitrite, nitrate and pH of the tank water.

Do a 75% water change and gravel clean the substrate every day for a week or until the issue is identified.
Make sure any new water is free of chlorine/ chloramine before it's added to the tank.