My skimmers need changed, water tested, sumps cleaned out and coralline scraped off of my glass. Field trip? I am kidding... which I guess needs to be pointed it out in today's age of internet creeperism.
I had sharks a long time ago. They are tricky and sensitive, but also quite hardy when done correctly. I am sure that you know what you need to know, but hollar if you have any questions. My main piece of advice is to find a local asian food market where you can buy anything from whole squids, octopus the size of basketballs, whole cuttlefish, etc. where the variety, quantity and cheap price is awesome for tanks with larger eaters. With a willing and eager club, you should have no trouble slicing and dicing them into nice sized hunks to freeze quite quickly. When I had small sharks, I had them order the smallest size of whole shrimp and had to wait - just the tails are not enough they need the guts, brains and livers and stuff too. Shells can be good depending on the type. Tangs are not great tank mates since they pick, especially when they get larger, so choose your species well. Believe it or not, some puffers and the more gentle planktivore type triggers are really good (and really personable) like Crosshatch, Bluethroat, Sargassum and even Pink Tail and Black Durgon - if you are patient you can find a lot of these fish that have been captive for a while and no longer fit in a 180g. Salinity is the main thing along with stray voltage - have a good refractometer and calibration fluid handy and even a cheap harbor freight voltmeter in your kit.
When choosing fish, planktivores in general are a good place to start - not fish that truly eat plankton, but that get food from the water column and do not pick at stuff. If you want the sharks to be out all of the time, then they don't need their slime coats picked at, even if the fish is just trying to get a piece of food that got stuck.
Let me know if you need any cutting boards, freezers, knives or anything else that always comes up later on... Adams Appraisal always will to make some donations and while mean old boss has been working me long hours, he lets me do whatever I want for this type of deal.
Looking Good.