Cleaning tank after betta death (and want to add new betta)

I'm pretty sure I know the answer here. I had a betta with a big tumor on his back. I went on vacation and got back today. Before that, he started to get a little wide and I suspected he would die over vacation (gone for a week) since this bloat wasn't going away. His tumor had more than doubled in size since I got him in Feb of this year. Came home today, and he was laying on his side and pineconing. I put him down. I'm eager to get something in his tank, a 20 gallon, to fill the void and so I don't have to try to keep it cycled by feeding it ammonia. My plan is doing my usual water change/gravel vac (maybe more than usual) before going to the store to get a new betta. Sound like a plan? He didn't have any other known diseases aside from this huge tumor that I suspect started to creep into his abdominal cavity from his back. No other tankmates and it will remain that way. Up to his death, he acted like a normal betta and was all over every inch of his tank. Very normal, healthy critter aside from his tumor.

 

Do a larger water change and test the water to make sure the parameters are safe.

 

I'm pretty sure I know the answer here. I had a betta with a big tumor on his back. I went on vacation and got back today. Before that, he started to get a little wide and I suspected he would die over vacation (gone for a week) since this bloat wasn't going away. His tumor had more than doubled in size since I got him in Feb of this year. Came home today, and he was laying on his side and pineconing. I put him down. I'm eager to get something in his tank, a 20 gallon, to fill the void and so I don't have to try to keep it cycled by feeding it ammonia. My plan is doing my usual water change/gravel vac (maybe more than usual) before going to the store to get a new betta. Sound like a plan? He didn't have any other known diseases aside from this huge tumor that I suspect started to creep into his abdominal cavity from his back. No other tankmates and it will remain that way. Up to his death, he acted like a normal betta and was all over every inch of his tank. Very normal, healthy critter aside from his tumor.

If he wasn't dead for a long time, as in disintegrating in the water, it is likely good to go now. Maybe do a big water change, but if you put him down before he died, its probably good in terms of ammonia from the death, since no fish was dead.

 

He wasn't dead in the tank, I had to euthanize him seperately. I did a good water change, tested and then got a new betta. He's doing great.

 

The tumor was likely genetic. Nothing anyone could have done - glad your new betta is doing fine!