I guess I should wrap up this thread then. The tank was really a lot of work to maintain. If I only had it, it wouldn't have been a big deal, but having it along with several others including the huge reef, it was just one more job that I didn't care for.
Topping off regularly was critical to maintain salinity. An ATO would be ideal, if you don't mind the look of a float switch. Water quality required many water changes. A huge sump hidden out of sight would be nice.

It would also have kept the temperature more stable.
Once Casper got sick, it was months of care trying to get her back to health. I think something got to her brain, because she couldn't eat properly and near the end of her life she was swimming upside down, scooting her head along the glass bottom. She's seemingly accidentally inhale mysis from the daily feedings, rather than actually catch any. After she died, I kept taking care of the Kuda, but I think it was infected by the Reidi, as it died about two months later acting quite similar.
I have a new tank that I'm planning to set up in the entry way of my home, and would like to put some seahorses in it at that time. It will be tied into the 280g's sump, so water stability will be simple to maintain.