I don't think a deeper tank is going to acheive much as far as a temperature gradient goes. There isn't enough water and it is cycled through the filter to quickly, that is if you have a decent one which you need to keep a tank clean..
Works in a pond as the deeper water is usually still so it doesn't mix with the warmer top layer...
Ben
Works in a pond as the deeper water is usually still so it doesn't mix with the warmer top layer...
Ben
