Just to add a little more to the D.I.Y. systems, here's a few pics of my filter for my 55 gal planted tank. It was made out of an old 25 gal tank. I used thick and high-quality Spanish wall-tiles to separate the chambers. They have a quite decent heat-retention capacity and with the heater in the filter tank it's more economical. A 200W Ebo-Jager turned on to 3 keeps the tank at 30C during the day and 28C at night. The rest you can figure out, no rocket science involved.