I have an idea on my mind for quite some time now. I already tested it with a set of buckets and the principle actualy works as i thought. Because by laws of nature it just should work. Tested it anyway. I'm thinking of an aquascape designed with twin tanks next to eachother. It shall be 2 low tech nano cubes. But i would like to make them like communicating vessels.. so i would like to connect them with a lets say 80mm acrylic tube bend in a U shape (maybe 2, 1 at the left 1 at the right side). These tubes will be on top and filled with water and by the laws of vacuum stays filled and wont drain. Tank 1 gets the filter inlet and tank 2 gets the filter outlet. Now because they function as communicating vessels the water level in both tanks always stays the same. What i pump into tank 2 gets sucket out of tank 1 I made a simple litte drawing to maybe make the idea a little clearer. Now the fish i like to put in there maybe a pair of dwarf puffers and some thet goes good with them, i know they are very intelligent and like to explore. I kinda expect them not to take long to discover the tubes and venture from one tank to the other and back. Theoreticaly i dont see any problems why this shouldn't work, running 2 tanks like that on 1 filter and heater.. Flow wont be a big issue since it will be low tech. i just want to like your opinions on this.. what do you think? Would an idea like this work. Are there any problems i could run into i haven't thought of..Before i start constructing and spend money on something doomed to fail.. You even may call me totaly crazy, i can handle that.. Still it's just an idea thats haunting me for some time now.