Why or how would a ledge or platform increase the numbers of fish that a tank can support?The surface area at bottom of the tank is important to the amount of fish you can have in it. A tank that is one foot by one foot and four feet high can't hold as many fish as one that is one foot by four feet one high. Adding ledges or building platforms using flat rocks well increase the number of fish your tank can support.
Its like a half truth. Cichlids, loaches, and cats will be able to sometimes stock in bigger numbers because they dont realize theyre near the surface.Yea... I'm confuzzled about that too, that would actually lower the area for fish to swim around wouldn't it?
Let me add that you should rehome the angelfish also. Angelfish definitely need more space than a tank with a 30" footprint can provide.Simplified answer: you must Take back the shark,
step 2 : pick one of the other 3 species as your main fish then go from there.