Betta Yawning?

... welp today I got a whole new tank and setup for a betta. I can’t control myself. Anywho, it’s a red and blue delta tail male. So I used fish tank water from a healthy tank and put it in the new one. I know it doesn’t have a lot of bacteria nearly any but I used it anyway. I don’t have a filter, but I am planning on planting the tank like a forest with a river. Swords Anubis’s java fern, jungle Val, and carpet the river part with dwarf baby tears. I am ordering a plant light soon to help them grow. So I added him in today, and he seemed a little roughed up from being at Petco. So he wasn’t that active, so I kept the light off. Every hour or so I turned on the light to check on him but every time he turns the light on he seems to stop moving. So I keep the light on only for about 10 seconds. I hadn’t checked on him in about 3 hours so when I saw him he was swimming around and exploring. Once I turned the light on he was still swimming but he started yawning? He flared up his fins and almost pushed the underside of his hills out. He did it multiple times so I quickly turned the light off again. I'm new to bettas also advice is appreciated. What was he doing? Was he scared or intimidated? I also have a 50 watt heater set a 78 degrees and a bubbler with an air control valve and a small bubbler.

 

It sounds like he "flared", which is what a Betta does when they think they see another Betta. It's highly likely that when you turned on the light, he saw his own reflection in the glass. It's not fear, it's actually aggression.

It will not do a Betta any harm to flare once in a while, and it is a normal behaviour, but if he does it constantly it can stress him out. You will need to be able to light the tank consistently for the plants, so leaving the light off is not a solution. If he's "flaring" at one side of the tank then you can add a solid coloured background to that side so there is no reflection there.

 

You say you have no filter in this tank but you do have a bubbler (like an airstone ?) Have you considered putting a sponge filter in there in place of the bubbler?

I agree with lilirose He is probably doing what male bettas do when they see another male. That is what his reflection looks like to him.

 

You say you have no filter in this tank but you do have a bubbler (like an airstone ?) Have you considered putting a sponge filter in there in place of the bubbler?

I agree with lilirose He is probably doing what male bettas do when they see another male. That is what his reflection looks like to him.

I have considered it, what’s a good one for a 5 gallon betta tank? Also I might paint the back and sides or just tape some back paper for a temporary thing. I’m only keeping the lights off so he can get used to his environment and not get stressed

 

I have considered it, what’s a good one for a 5 gallon betta tank? Also I might paint the back and sides or just tape some back paper for a temporary thing. I’m only keeping the lights off so he can get used to his environment and not get stressed

I run in my smaller tanks. In fact I keep 2 of them running all the time in my big tank. That way when I need to set up a small tank I just pull one and put it in the small tank to instantly cycle it.

Blocking your little guys view to the outside world for a while should help calm him down. I would cover all but the front for a while. Eventually you could remove the covering from the sides.