You can often find used aquariums in garage sales too.
If you try and build your own, you need a way to make precise cuts. And the cut edge should be smooth. The Acrylic cement I've used is thin like water and it wicks into the joint. You have to have the pieces clamped and square before applying the cement. It can be done, but you have to be perfect.
You'd have a better chance with glass as the silicone rubber cement is much more forgiving. Clamping etc is still needed. Must have square corners. You will need a diamond file to smooth off the glass edges before joining, unless you have a torch to round the edges by heating the glass. Fire Polishing.
What plants are you thinking of growing?
