I took some scrap/leftover tabletop 3mm glass, crudely cut it (I totally suck at making clean cuts, but it was good enough for my use case.), silicone sealed the panels together (Silicone is the anti-Christ! Unless you have a specialized "silicone injection setup, complete with 45 degree angle clamps and an industrial silicone pump, it's virtually impossible to do this step neatly.) and viola!, another DIY 15 gallon fish tank (whew)!!

Notice how I reinforced all corners and an uneven, weak spot with glass ampule wedges. I learned this trick from another DIY aquarium builder online; of course, after many previous failures.

Now I am currently "cycling" the tank for a couple days before testing the water.

If the PH is around 8.0, ammonia is zero, nitrites are zero and nitrate level is <25ppm, then a few of my fish are gon'na get a new less crowded home.

Submitted FYI.

May you and yours be well and loving life today.

In Lak'ech,

JaiChai