All parameters are good and ph is fine. it is only that one endler.What are your water parameters? Even if you just did a water change and a vacuum job, sometimes there can be debris that was missed and is causing an ammonia spike. I’d test the water first and foremost, and once water chemistry is confirmed or eliminated as a problem you can move from there.
All parameters are good and ph is fine. it is only that one endler.
Now its moving around like normal. possibility it was a napping during that time.Does he have any visible marks or ailements when you watch him (other than staying at the top)? Also, does he seem bouyant, like he might have a swim bladder issue?
Also if I could have your nitrate ppm that would be great info to have just in case.