URGENT HELP! Drastic behaviour change

[FisheeFishee12345]

My betta was all okay n fine in the past. However today i added just 4 neon tetras in the tank. Everything seemed fine as the betta was not chasing the tetra neither were the tetra disturbing the betta.

However in the evening later on, i just moved my face to the tank and my betta literally swam REALLY FAST to the back of the tank n stayed there for a few good seconds before coming back out. By really fast i mean ridiculously fast, pretty much faster than a tetra's movement. This happens a few times. Sometimes when i move my face to it it doesnt do that but other times it does. I've never seen my betta act like that before and it is used to me already it even takes food from my hand. So i dont know why it suddenly got this startled by me. Is this caused by this huge stress from its new tankmates or something? This is pretty scary for me as it was really fast in rushing to the back n hide behind the filter.

Also just some additional information i recalled, usually im not wearing my glasses but when i moved my face the first time it swam like that, I was wearing glasses. Maybe its the reflection from the glass or smth?

[Whale93]

From my experience 4 neon tetras should not affect a betta too much. Unless your tank is really small maybe? It could be your glasses(maybe the betta saw itself in the reflection and thought it was another betta) or maybe a unintentional change in water chemistry that stressed your betta.

[FisheeFishee12345]

Hi Whale93 thanks for ur response! Hopefully its my glasses. Never reared other fishes together with a betta before so kinda stressed out by the reaction.

Also when i turn off the lights the tetras go into a frenzy but i guess this will be over after some time once it gets accustomed to the day n night routine? My betta also starts attacking the neon tetras when lights out possibly because it mistaken them for another betta with that glowing strip on the tetras? Really hope these two can get along fine as I cant tell if either of the party are stressed out by each other or not yet.