Fin rot or nipping/tear

I've had my halfmoon betta, Darkwing, for over two months now and it's recently come to my attention that the rough edges of his fins might not be their natural shape.
If I really think about it, they've been like this the entire time I've had him so it might not be nipping but it did get worse after he was in a 20 gal community tank with some African dwarf frogs (he was put in a tank by himself earlier today once I confirmed he was clamping his fins).
So I guess I was wondering if anyone could point out what's actually going on with his fins and how I should go about helping him.
For some more information he's in a 1 gallon bowl (this will be changed to something much bigger as soon as I can but we're moving to a different state next week so I'm waiting to give him the home he deserves) with a heater. He hasn't lost interest in food and still comes to the front of his tank to say hI whenever I go to check on him.
(Hopefully the pictures are okay he wouldn't stop moving)

 

Keep an eye on his fins, but I don't notice anything unusual about them. If you're worried it could be fin rot, do a couple of extra water changes as clean water can help a lot.

About the one gallon; I'd just say stay on top of your water changes (and do them more often and extra) as you'll need to do the job that your filter would usually do. Do you have any sort of air pump running in there?

 

Keep an eye on his fins, but I don't notice anything unusual about them. If you're worried it could be fin rot, do a couple of extra water changes as clean water can help a lot.

About the one gallon; I'd just say stay on top of your water changes (and do them more often and extra) as you'll need to do the job that your filter would usually do. Do you have any sort of air pump running in there?

Wait those plastic plants look like they have sharp edges on them... That could be the reason for his tail looking different as their tails are pretty delicate.

 

Wait those plastic plants look like they have sharp edges on them... That could be the reason for his tail looking different as their tails are pretty delicate.

I don't have an air pump currently in the tank he's in now. Should I get one? I've read that they can be helpful but that some bettas don't like them. I'm worried about agitating the water too much but I'm willing to try it!
As for the plants, I'll remove the plant that's possibly sharp and replace it with something softer in case that's the problem!
Thank you!!!

 

Honestly I would just do 25-40% daily water changes. That will keep your water quality good, help heal the fins, and replenish oxygen which will prevent the need to put out $ for an airstone (not that an airstone is a bad idea). I always recommend the 5.5g kits from petsmart. I love mine and it was very affordable (30$). Comes with a filter, hood, light, and thermometer. I keep the filter on the lowest flow option and have a sponge around the intake.