I started making the fish a little bit differently, adding more detail and making the eyes less "buggy", using really great glass & making them smaller.
The tall skinny aquariums are very popular because they are perfect for a desk or small area.
Then I started getting requests for larger aquariums with tops and sand.
My very latest is an aquarium has all the same color combination of fish. I also changed it up so that the kelp is glass instead of copper. I also made the lid removeable instead of adhering it. It gives an option. The sand is also not loose also.
Who knows what the next version will be!