Seahorse Frequently Asked Questions / Can I keep a Sea Dragon in an aquarium?
Short answer: no.
Long answer: Sea Dragons have very specialized needs and are very expensive. Leafy SeaDragons cost around $4000, and there are limited numbers available because of export rules in Australia, so most go to public aquariums. They also need very specialized aquariums that keep the water clean and cool, as they are a temperate species, coming from the colder waters around southern Australia. Weedy Seadragons are less expensive, but still need very large, expensive setups.
The first hurdle is the aquarium. They need very large aquariums, at a minimum of 500 gallons, and that is a minimum with most being kept in much larger setups. The cost of an aquarium for sea dragons can easily exceed $10,000. On top of that, one would really need to have extensive experience not only with fish, but with syngnathids (the seahorse family of fishes), and would have to have access to a vet who has experience with syngnathids.
Most zoos and aquariums end up feeding live food because of the problems with bacteria and frozen food, which can cost a few hundred dollars a month to supply. Some places do grow their own food, but it is very labor intensive, and needs a large area to raise enough food to produce enough food. For example, the Shedd Aquarium in Chicago has a setup that is roughy 20′ long by 6′ wide by 8′ tall for raising mysis shrimp and has a staff of aquarists that maintain the mysis culture.