Looking to attach 2 nano tanks side by side

[Fishyj]

Hello all. I am looking to attach a 13 gallon Aquatop tank to another one. One of the tanks would be my display tank and the other one would be a macro algae display tank. I am looking for the safest way to accomplish this. I thought about using 2 pumps and 2 sensors to do this. Any other ideas would be appreciated.

 

[Hairyteeth]

Drill them both and connect via a sump?

 

[Fishyj]

I really don't want a sump and I did to mention they are aio