My niece left for college this morning and unbeknownst to me plopped her Betta in my 10G quarantine tank. The tank was empty (just ended quarantine on some rainbows 2 days ago). Poor thing just sits on bottom of tank for last 2 days. He did eat though. I keep thinking he's dead but he moves if I prompt him! Any clue what's wrong? PH swing? Water parameters are fine. Any guesses?