One of the most important, and typically the most overlooked, steps in properly setting up an aquarium is making sure the stand is level. For whatever reason, most stands aren’t perfectly level, regardless if they were made by a big name manufacturer or were a DIY project. This issues is compounded with the stand is placed on a hard surface, such as a tile or concrete floor. When the stand isn’t level, gaps between it and the bottom of the aquarium can develop. These gaps, even though appearing small, can actually put a great deal of stress on the glass or acrylic, and might possibly lead to a tank crack down the road. So, make sure the stand is completely level before filling the aquarium with water, and be sure to check for gaps that could cause issues in the future.