My betta is very strange

[Arizonagrace]

I recently purchased a very cute 1.5 gallon tank to use as an isolation/hospital tank in case of emergencies.

I went to change my bettas tanks a few days ago. Instead of putting my purple betta in a cup until his water was changed, I placed him in the 1.5 with his old water so I could thoroughly clean his 5 gallon tank. After cleaning it, I moved him back to his 5 gallon.

He swam around a little bit, went to the bottom and laid there for hours, only coming up for air. He didn't eat for 3 days.
This went on for 3 days. I went into a panic thinking I didn't add prime or something, so I put him back in 1.5 and redid his 5 gallon. When I came back to move him into the 5, he was happily swimming around in the 1.5. I added new water and put him back in the 5 gallon. He quickly went to the bottom and wouldn't even look at me like he always does. He is an extremely friendly betta and will always come visit me when I look in. If I put in a finger, he will swim around it and have fun. But, he suddenly wouldn't do anything.

I thought about this awhile, and decided to put him back in the 1.5 gallon to see what he would do. Put him in, and he began swimming around and became the playful guy I have always loved.

I could only figure he likes the 1.5 gallon better, so I experimented with my other 3 male bettas. I purchased 1 more of the 1.5 gallon tanks and did the same routine. 2 of the 3 other bettas reacted the same way, going to the bottom and sulking. The 3rd didn't really care what he was in.

These are very cute little tanks, and have an led light and a tiny filter in the tank and I added marble gravel to the bottom. I now have 2 very happy bettas in 1.5 gallons, 1 betta in a 5 gallon who is doing nothing but sulking and not eating, and 1 betta in a 5 gallon who is a happy camper.

Is this kind of behaviour unusual? I know bettas are personable and pretty smart, but could this actually mean they prefer the 1.5 over the larger 5? Or am I just a crazy betta lover. I am seriously tempted to use the birthday stash for more tanks for these guys.

What do you all think? My niece says the bettas are crazy and I am doing fine mentally.

 

[>:(]

Maybe something to do with the fact that the larger tank would have to cycle again once you cleaned it out "thoroughly?"

 

[Arizonagrace]

I didn't change much for the 5 gallon, just took out all gravel and water and rinsed it out well and put it back in. done it that way for months. There was just an air bubbler in the 5 gallon tank, but the new has a regular filter.

 

[>:(]

I didn't change much for the 5 gallon, just took out all gravel and water and rinsed it out well and put it back in. done it that way for months. There was just an air bubbler in the 5 gallon tank, but the new has a regular filter.

Well, that's part of the problem. If you take out the gravel and rinse it, you've just gotten rid of the majority of your beneficial bacteria. If there's no filter, the BB don't have many places to go but the glass and gravel, and if you take out the water and gravel, you kill most of it. So, it probably does do at least a mini-cycle when you clean the tank like that.

I think 1.5 gallons is very small for a betta, and a filter in a tank that small will probably create a current stronger than most bettas enjoy.

 

[Angel51087]

as above, doing a thorough clean is unnecessary and totally detrimental to the fish. Re-cycle the 5 gall, put him back in there and do a 20%wc weekly, he'll be happier in there than in the 1.5