This ant farm is supposed to print in 3 printing-friendly parts:
The body is made to fit a 95,15 mm inner diameter cylinder (preferably acrylic, as glass usually have tolerances up to 2mm) But I suggest to printing scaling it to your needs with your slicer. To do it, first select the main cover STL which would give you the exact diameter of the ant farm body, scale it to your requirements and use the same scaling on the other files.
Depending on the filament used, you may need to varnish the deposit and body interior in order to prevent leaks. I suggest to place a strap of PVA foam in the bypass between the both areas in order to let through the moisture and just keep the tank filled with water, preventing possible damages flooding the lowest chambers.
One of the lowest chambers is drilled with five 1mm holes in order to let moisture get into the farm. I highly recommend to place some stainless steel woven mesh on the inner wall of the body (easily done melting it CAREFULLY with a soldering iron). This is a MUST in case you plan on putting small species in there. Once all the inner needs are done, you just need to place the main cover and glue it to the main body (be extra careful lining up the access hole).