I have a 90 gal with nothing but crabs and live rock. No fish at the moment. I had to take a break from them due to problems with disease. Anyway, I am currently researching on how to feed fish the perfect diet. My question is about vitamin supplements. I was feeding my clownfish frozen brine plus and my tangs sea veggies and some spirulina flakes. I think next time I should use some vitamin supplements. Is selcon the answer or vitachem? Also, how do you apply this stuff? I would imagine it dissolves off of the food when it hits the water but then again I don't know. So, which should it be? Or should it be both?