HELP! My fish might have Shimmy!!

[Heat]

My fish swims in place. I don't know if its because he is exited to see me or if he caught Shimmy from the pet store he came from, but just in case, will you help me know how to cure my poor fish? So far, I'm replacing like 20-50% of the water each day and I just took out one of the fake plants and cleaned it with warm water, just in case it had fish poo or leftover food on it (and it sorta did).

[Mister Sparkle]

Bettas aren't very prone to getting the shimmies. What you are observing could very well be very natural behavior. Bettas do like to swim in place from time to time...is he doing any rubbing?

[Heat]

Oh. WHAT A RELIEF! :D I don't even know what rubbing is so I'm afraid I can't answer that question. xDDDD

[Mister Sparkle]

Rubbing against stuff excessively, as though trying to get something off himself. That's the sign you want to watch out for.