I kept seahorses for awhile...my own stupidity killed them...i moved my filtration stuff to the basement and piped it up through the floor to the tanks...when I did this I increased the flowrate from about 400gph to about 900....the excessive pressure stressed the horse to the point of no return....my plan was to put her in a smaller tank co-located to the 45 she was in....but I wasnt completely finished with the smaller tank so i left her in the 45...
Seahorses are difficult to keep due to their unique feeding habits, and habitat. They require continuous attention for feeding and require pretty much prestine water quality...mine fed on live food only...so i kept a 5 gallon tank in the lower portion of the cabinet with air and heat for live brine shrimp....that was tasking in its own..
If one is willing to devote the time and energy into them...they are very very entertaining and fascinating to watch...tons of research would be the key for this...