I've bought a small, used aquarium (one of the 5 gallon Mini-Bow systems, where the tank bottom and sides are all one piece of acrylic - injection-molded, I assume?) and while cleaning it out, I discovered a few cracks in the bottom of it.

The tank hasn't leaked at all (I had it full for a day before noticing the cracks - but with no fish in it, thankfully!) and when I scratch at the cracks with my fingernail, I can't feel them in the surface, but they're definitely full cracks (not just scratches). There are 3 of them on the bottom of the tank, each about an inch long. Attached are pictures, though they're not really necessary?

So I'm wondering if/how I can repair this (inexpensively)?

A Google search has pointed me towards acrylic cement (Weld-On), but (A) I have yet to find a place in Canada, where I live, that sells this, and (B) looking at prices for it in online stores, buying a $20+ tube of Weld-On will defeat the purpose of my being cheap and buying a $15 used tank. :)

Knowing that methyl methacrylate is one of the ingredients in acrylic cement, can I simply use frag/Super Glue to repair these? Will it effectively "melt" the plastic back together?

Any advice is greatly appreciated!

Acrylic Crack 12.JPG
Acrylic Crack 2.JPG