Outstanding idea.

And I ordered a 44 lbs bag of azomite. I read about it and found out it is good for so many different things. I wounder if any one has tried to take some as a dietery supplement?!?!

I think I will try this; I think this might work :
Mixing whole wheat flour, ground corn or corn meal, crushed oatmeal, maybe some grounded chia seeds and then some brown sugar or molasses. Mix all with some water, make something like bread dough and bake for a little. Or as it was mentioned above, just let it sit in refrigerator.
Then crumble it according to the size of fish into the fish tank.
Oh, I forgot to mention that I will also add some azomite to it.