Tank dimension? Any eurobracing.. Just take note that the tank is not warping when salt water is added...
12mm seems to be on the thin side...
And it is true if you want to keep fish only, chiller is not required but the color will not be as vibrant as in a cooler tank..
There is actually a table that match the flowrate to the pipe size... I am using that and no problem so far almost a year liao.. and it is self priming...