Under these circumstances, the fish seem to be more tolerant of each other, allowing different species to exist together peacefully. There are some specific guidelines that interested hobbyists should adhere to when considering a water garden for tropical fish. The size and shape of a tropical fish pond are very important. There are a couple of reasons for this. A small, shallow pond affords the pondkeeper the opportunity to maintain visual contact with the fish.
High visibility is very important.
In addition, a shallow pond allows algae to grow faster, providing plentiful amounts to those fish that require it in their diets. I have devised three categories of fish to give the potential pondkeeper an idea of which species make the best pond fish and why. The fish in this group are both highly visible and hardy. As a result, a pondkeeper might go for some time without seeing these fish. Because of their rapid growth, when the pondkeeper finally does spot them, they are often much bigger than expected.