Midwest Custom Aquarium offers cylinder aquariums built from 2 separate halves. If you need a certain diameter that is not offered in a seamless version or simply want to save some money when compared to a seamless tank, this may be the better option for you. Tanks built this way will have 2 vertical seams. They are not readily apparent and appear as a thin line or a narrow distorted width.
Some manufacturers will call these seams “invisible”, which is misleading. If you can find them they are not truly invisible. Below is the general sequence for building a cylinder from 2 halves. The same process is used for bullnose, double bullnose, and other shapes.
#1. A mold is made to the correct diameter and the two halves are thermoformed in the oven. They are then machined to exact tolerances and are ready for bonding.
#2. The 2 halves are professionally bonded and the resulting seams are then sanded and polished to make them as invisible as they can be.
#3. The bottom, overflow (if necessary), and top are added to complete the aquarium.
#4. Finished tank. This is a close-up picture of a vertical seam where two halves are bonded together. Seam runs right through the blue tape. If you are looking for the seams you can find them. They are not readily apparent if you are not. We have tried many times but it is usually not possible to get a seam to show up in a picture.
Here is another example of a seam in a cylinder aquarium built from 2 halves. The seam is in between the arrows.
Here is an example of the main body of a double bullnose that has vertical seams. You will not find them in the picture but they are there.