New Betta, Need Input

I lost my only Betta overnight to a rather depressing jump from his new tank (I was strongly pushed to move him by fish folks to the larger tank rather than leave him in his 5 gallon that he seemed quite happy in). He'd always shown an interest in jumping, even would swim up the filter outlet on the original small tank I'd gotten as a temporary home. He'd go UP, flop down the spout, and go right back to it. This new tank had a way out I didn't imagine he'd be able to make but he did.
I wasn't going to get a new Betta just yet - figured I'd clean out the tanks, maybe move them slightly, etc., then the fish friend cat came in 5 times to check for his buddy (my betta would sit next to him blowing his bubble nest, and the cat would just lay down and watch him for a while) and the sight of 2 empty tanks on my desk kept dragging me lower and lower.

SO! I ended up popping in to one of the semi-local big pet stores that I hadn't checked out before to see how their fish selection was. Just in case one called to me.
And I was horrified at what I saw. It wasn't just one fish, it was over 2 dozen obviously sick fish, several dead fish, and rotting material on the fish cups. I almost ended up with 15+ new bettas.

I ended up with 1, for today. I don't think he's 100% healthy and I need some help on figuring out what it is and what I should do right away.

I'm guessing fin rot (most of the other sick fish had severe cases of it), but he also has this weird... swim dance? to get to the top of the cup. It's an odd twist. Not always, but sometimes.

Should I put him in the lived in 5gal that my other betta was in? It still has bubble nest remnants... He seemed to be healthy with increasing color, just liked to take chances that didn't pan out. (I miss him a lot)
Or do I put him in the new 10gal that is stocked with nearly all the plants now? And is less cycled.
I can clean out the 5 gallon and relocate the plants. I can pull the 2.5g hospital tank in and set that up if a smaller setup would be good while he heals?
I don't want to move him from tank to tank, but I do want to get him started as well as possible.

(The Galaxy Koi is my last Betta buddy, and his 5 gallon tank)

 

I personally like to put bettas into uncycled 2.5 gals when I'm trying to heal them of something or other- it reminds me to do daily water changes which helps keep the water super clean. I agree that it looks like he has fin rot. Not sure about the weird little twist you mentioned, best to keep an eye on him for now.

A good way to finish cycling your other tanks is to dump the dirty water from his hospital tank into them- like a water change but instead of fresh water use whatever you take out of his current home. This will supply the tank with an ammonia source without risking your fish's health. I cycled my betta's original tank this way to avoid doing a fish-in cycle.

Once he heals I personally think the 10 gal is the best option. However seeing as you said your previous betta jumped I'm assuming it doesn't have a lid? Is there a lid for the 5 gal? Basically which ever has a lid is better, it'll help prevent sky diving.

 

I will pull the 2.5g out of hiding shortly. I had put it away when I upgraded the last Bettas living space.

Both the 5 gallon and the 10 gallon have lids, but they have holes in the lids that he tried to get through. I had covered the 5 gallon (that has a subpar filter flow) lid with saran wrap but noticed some weird algae like growth (maybe mold) in the tank and tons of moisture dripping in, even with a gap left at the top. The 10 gallon has a stronger filter, with a MUCH smaller hole, that was 2 inches down from the water. My previous Betta apparently saw that as a challenge he couldn't say no to. He achieved jumping success sadly.

I will cover the hole in the 10 gallon one way or another if there's another fish in there. I will cover the 5 gallon hole with mesh when it arrives, whether it's this fish or another that takes it.

Thank you!

 

A betta will do just fine in a 5 gallon tank, although a bigger tank is always better. For now I would leave the betta in the tank he is already in to avoid stressing him out. Until you can get the 10 gallon fully cycled then I would move him in there when he has recovered. Also get some sort of a cover, lid so he doesn’t jump out.

Another thing I would like to mention is buying Bettas from stores that do not treat them well. When you buy 15+ Bettas the store only sees this as more products being sold. When you buy from these bad stores, you are supporting and enabling them to buy even more fish in crappy conditions. Instead, it is better to not support these stores and give your money to help responsible breeders who truly care about fish.

 

I would use the 2.5 until he heals. Looks like fin rot, which can usually be treated by daily water changes and maybe some aquarium salt. The 2.5 will allow for easier water changes. Plus, salt will kill plants so you wouldn't want to treat him in one of those tanks.
After he heals, I think that 5 gallon looks like a great home for him.

 

He's not in any tank at the moment - I just brought him home. I was mid tank switch after my last Betta died.

I didn't buy the 15+ fish from them, because I don't have the tanks sure, but mostly for that exact reason you bring up. Making it ok for them to treat this way. I don't normally even consider buying anything (even pet food) from big box stores, however in our area it is the only store in 3 counties that carries the food I need at the moment.
I did purchase this guy because I couldn't stand the idea of leaving .. anyone behind in that.

Before I left I pulled several employees and a manager into a very public discussion, and I will make sure that they step things up this week as they said they would. I will also be reaching out to their district managers and corporate offices. I will never purchase from them again but I will do all I can to ensure that the fish and customers are treated better going forward.

I would use the 2.5 until he heals. Looks like fin rot, which can usually be treated by daily water changes and maybe some aquarium salt. The 2.5 will allow for easier water changes. Plus, salt will kill plants so you wouldn't want to treat him in one of those tanks.
After he heals, I think that 5 gallon looks like a great home for him.

So 2.5g tank, no living plants, clean "new" water with salt?

 

I did the same thing a few years ago when I got my betta. I went in for fish food and he looked so sad so I bought him. Casually mentioned that the rest would appreciate some more clean water on my way out. :s

I treated Fancypants with 100% wcs daily and salt as instructed by the box. His fins were growing back within 5ish days and looking better than when I got him after 8-9 days. I used Prime and Stresscoat.
No living plants. Maybe a silk plant or a very smooth decoration to hide in. Also a heater, and try to keep the temperature constant to prevent more stress.

 

I did the same thing a few years ago when I got my betta. I went in for fish food and he looked so sad so I bought him. Casually mentioned that the rest would appreciate some more clean water on my way out. :s

I treated Fancypants with 100% wcs daily and salt as instructed by the box. His fins were growing back within 5ish days and looking better than when I got him after 8-9 days. I used Prime and Stresscoat.
No living plants. Maybe a silk plant or a very smooth decoration to hide in. Also a heater, and try to keep the temperature constant to prevent more stress.

Oh good! I was wondering how long that might take too.

Do you think it would be ok to use the 5 gallon tank? I will move the few plants left to the 10 gallon and put in a couple soft silk plants. It has a heater and a very soft filter that won't toss him around too much. (The 2.5g minibow has a wicked powerful filter system on there I fought with until I got the 5 gallon for my last Betta)

Thank you so much!

 

Yeah, the five gallon would be fine! Just more salt & water to deal with.