Thanks Pete. (Always helpful as usual.)
I read your reply, and the referenced thread as well. I should note that I’m almost certain that my seahorse is not pregnant. Also, I saw this quote in the other thread:
It will struggle mightily in a losing battle against its increasing buoyancy until finally it can no longer swim at all, bobbing helplessly at the surface like a cork whenever it releases its grip on its hitching post. At this point, its pouch will be obviously swollen and bloated.
The swimming behavior ("like a cork") is exactly what I’m observing. However, the pouch is not "obviously swollen and bloated".
My seahorse appears (visually) perfectly normal. Just bobs like a cork. (And isn’t eating.) But no pregnancy, no swollen pouch, etc.
I’ll try a pouch flush anyway. Maybe it’ll help.