Hi,
Im just trying to design a closed loop for my tank. using Pies idea of actually "drilling" and plumbing up holes in the tank at the back/bottom or underneath, my concern if a pipe accidentally popped off the loop somewhere, it would drain the entire tank. So, thinking of how typical sink pipes work, i thought about designing the loop as follows (specifically the yellow pipe design)
Side on shot of the tank:
The worst that could happen here if a pipe popped off the pump (or anywhere except the connection attached to the tank itself) the tank could only drain down to the water line shown by the red line above. This design could work with those without "in-wall" tanks, as long as you had a hood you would see the pipe sticking above the water level.
Can anyone see any issues with this design or offer any advice? Cheers.