Rhapala.....a 10g tank is not a good size for any seahorse. It is too big for dwarfs and too small for anything else. You may want to research the tank requirements for the species you are interrested in. I know of a few people who keep a pair of Kudas in a 20G high tank. I would never go any smaller then that. I personally don't think anything less then a 29g is a good home for them. Could they live in a 10g...sure. Would they be happy....probably not. It's up to us to provide more then just the minimum requirements. Make them happy.......and you will be happy with them. Good luck.
Rhapala.....a 10g tank is not a good size for any seahorse. It is too big for dwarfs
Not necessarily true... depends on the number of Zosterae you want to keep. My first ever seahorse tank (in the early 80's) was a 10 gallon dwarf tank that ultimately housed a dozen zosterae. Should you put a pair of dwarves in a ten gallon? No, because you couldn't concentrate their food enough for them to feed properly. However, in numbers, this would be okay.
Also, given that today's market puts out various dimension tanks, a "gallon" rule wouldn't be appropriate. For instance, the Via Aqua 12 gallon tanks are tall and thin. They are WONDERFUL for dwarves if kept in herds of a dozen or so.
A ten gallon tank is far too small/short for any of the larger species...as you said...
Could they live in a 10g...sure. Would they be happy....probably not. It's up to us to provide more then just the minimum requirements. Make them happy.......and you will be happy with them.