I just did a 95% water change for Liberty's tank. I took him out and cupped him while I churned the gravel and then scooped all of the water out. (I do NOT do this for every water change, just did it today because Bertie was lookin down, and I had just cleaned his water yesterday). After filling his tank back up with clean treated water, I floated his cup for 20 minutes, adding a little of the new water after 15 minutes. After 20 minutes, I gently scooped him up with my hand and put him in (nets used to hurt his fins and scales). For about 15 minutes afterward, he wasn't using his right pectoral fin. He used it a little when he flared, but that's all. I think he's kind of using it now, but not as usual. Is this a serious problem?