New Tank Above A Radiator?

[paul_r_miller]

I am 18 months into keeping tropical fish and have a small 50L tank with a selection of small fish (tetras, a betta, etc). I want to move on to a larger tank 400L (ish). I have no obvious location for such a tank. I have read that one should not position a tank above a radiator, although I do not understand why not (convection heat from the radiator, when it was on, would obviously increase the water temperature, but with a thermostat in the water heater housing I cannot see the water temperature ever rising above the desired 25-27 degrees).
A 400L tank would require a substantial base/platform. If I were to build a very well supported shelf above the radiator, with a layer of thick insulation between the shelf and the tank and with a shelf that is significantly deeper than than the tank (such that convected heat rises in front, but away from the tank) would this arrangement be suitable for keeping tropical fish?

 

[smurfyy_2k3]

i wouldn't want to be the one to risk it, however the thermostat in the heater will only stop the heater from heating the water above that temperature there is no way for a heater to keep a temperature constant