switching tanks?

[Capricorn]

Okay, so I have two bettas at this point.. Nettlestung, my halfmoon male is in a 10gal to himself, and Starchaser, my king plakat, is in a 5gal to himself. The more I got thinking, I realized I should probably switch the two of them. Nettle swims around a bit, but doesn't really utilize the entire tank (likely because of his fins).

Do you think I should switch them? If I do, should I just give both tanks a good gravel vac/water change before moving them?

Thanks for your input in advance. <3

[JKfish]

If you decide to switch them, assuming they're both healthy and not sick, it'd probably be easiest to swith them after a water change.

[Capricorn]

Yeah, I do both their tanks on the same day, and they're due to get changed tomorrow.. I'll have to move decorations around a little, but I think it'll work out well. O: