Tips for building a fish tank out of Plexiglas or other acrylic sheets include ensuring the proper thickness of acrylic material is used, ensuring the seals dry completely before adding water, and conducting a dry assembly run. Additionally, it is important to sand the edges to ensure a tight seal.
The greater the volume of the fish tank, the thicker the acrylic needs to be to withstand the pressure created by the water. Roughly, for every 6 inches of tank height, increase the acrylic thickness by 1/4 inch.
Conducting a dry assembly run ensures the tank fits together correctly before welding any acrylic together, which cannot be undone without damaging the structural integrity of the acrylic.