We will need:
- glass cutter,
- glass
- sealant,
- gloves
- ruler
- marker
- grinding stone
- electrical tape
- razor blade.
1 step we take glass and put marks on both sides.
2 step we put a ruler and we carry out a glass-cutter on it.
3 step, carefully disconnect the glass with gloves.
4 step cut all sides.
5 step grind all the edges of the glass.
6 step degrease all edges of the glass.

7 step glue sealants.
Step 8, glue the joints with electrical tape or make such an edge.

Or so
As you prefer.
Step 9 we remove after drying the excess sealant with a razor blade.
It is necessary to fill the aquarium with water for three days. If there is a leak, glue it to the sealants.

I introduced you to a small and simple aquarium, but you can big:

Or a different form:

Look for others homemade for aquariums at bestdiy.washerhouse.com
Good luck to aquarium lovers.