Ammonia was at 0. That was the first thing I checked. He wasn't skipping. It looked almost like he'd lose balance. he'd be swimming fine then suddenly the top fin would puff up and he'd just crash. Repeat. Very strange.
No progress on the tank. Had a busy weekend. A lot less spare time than I was hoping for. Finishing smallreef up, then all energy will be poured into the tank. If i'm not done with fiberglassing by next weekend, i'll be surprised.