It’s good to hear that your female Barb is back to her old self again! That suggests that her problem was indeed an underinflated swimbladder, and that she has managed to secrete enough additional gas into it to restore neutral buoyancy and correct the situation. As I mentioned, that’s one problem that seahorses are often able to resolve on their own and that seems to be the case with your H. barbouri.
In that event, no treatment should be necessary, Jana. The fact that she was able to readjust her gas bladder so quickly seems to indicate that her brief problem with negative buoyancy wasn’t triggered by internal parasites or any sort of infection. As long as she is eating well, swimming normally, and maintaining her normal upright posture again, there’s no reason to medicate her or her tankmates.
The next time you’re at your LFS, you might still want to pick up some metronidazole for your fish room medicine cabinet. It’s a useful medication for seahorse keepers to keep on hand.
A water temperature of 71°F-72°F is great for H. erectus and tropical/subtropical seahorses in general, but H. barbouri likes a little warmer temperatures than most seahorses. I wouldn’t warm up your aquarium temperature at this time, however, since with summer fast approaching, your seahorse tank will probably be running around 75°F soon as the ambient air temperature rises.
Best wishes with all of your fishes, Jana!