I had a salt water fish tank for about 3 years, and growing hydroponically is nothing compared to the money, time, work it took. Besides salt buildup all around the aquarium any you put 2 fish in the tank 1 will beat up the other and that makes them sick.

Star fish die in days and are a mess, crabs get out and they will be running around your house, eels jump out and eat the alge eater even though the fish store says no way no one eats the alge eater. No live rocks live long unless your trying to keep live rocks not fish.

I went and got a cat and life has been much more entertaining. You can plan on spending half a day every 2 weeks. NOt including if you need to go get your water for the water change. When you say money, we are talking $1000 at least in the first 6 months and I had a 20 gallon aquarium............and it took that much time.