Is it similar to this one
? Hex tanks due to their height need excellent water movement and surface agitation to work for SW
doesn't exchange oxygen as well as FW
but other then that it's ok. I assume you have never medicated your FW
IMO Volitan Lionfish
need a little bigger tank but there are a few Dwarf Lionfish
to choose from that would work well with your tank size.
If you get 1.5-2+ lbs of base/live rock and a quality skimmer it would provide all the biological filtration
My "Stock list and tips for maintaining your SW tank"
post that has all the equipment listed that you will need and maintenance tips to help you enjoy your SW
tank. It's a long read but will help answer all the basic questions.
More helpful info:
If looking for cheap live rock checkout intmarinefish.com
which has lr
for as little as $3-$4 per lb shipped.
Couple of more places with quality lr
For base rock checkout Marco's base rock
(currently out of stock). You can buy mostly base rock and seed with 30%-50% live rock and it will all be "live" within a year or so.
Post on feeding requirements of SW fish.