Weld-On #4 vs #42

[Nonya]

Laser

Just noticed that your first post said the parts were laser cut and then you said later they are CNC cut. I would be sure they are CNC cut. If not you must sand the edges. I start with 150 grit and work down to 400. My laser leaves micro grooves that will create gaps/bubbles. These never leak, but the bubbles look like crap on clear. Colored acrylic will hide any bubbles or cracks, but they are weaker joints. If you calculate the dimensions you have given you are looking at 250+ gallons of water.

CNC describes the type of machine itself, not the manner in which the material was cut. CNC can use high pressure water and abrasive, router, or laser.
Agree that laser cut would be a problem. Heating the edge while cutting changes the properties of the acrylic at the edge.