Excellent vitamin supplements include Zoe, Selcon/Zoecon, Garlic Extreme, and VitaChem. I use all 4 of these every week in my fish's food.
Make sure your fish are getting a huge variety. Keep in mind, fish do not eat one or two things in the ocean. On a weekly basis, they might have 10-20 different things in their diet. This is why formula foods are very beneficial to your fish. If you use frozen formula foods like formula A/1 and B/2, your fish can get clam, scallop, krill, shrimp, zoo plankton, phytoplankton, squidd, prawn, mussel, fish, fish roe, among other things. Then, if you throw in algae formula, they will then get kelp, algae, lettuce, spirulina, and other greens.
If you are not going to use formula foods, you will need to pick up many different types of food so that your fish are getting a very large variety.
Just as a side note, I really do hope that you don't plan to put any more fish into that tank. It is quite full of large fish. Just the panther grouper and snapper will equal 50 inches of fish when they are fully grown. :scared: Then, you have 2 puffers in there as well. Yikes.