Poking about in Aquotix the other day in my usual fashion, I saw this and thought it was neat.
It's the Eden 522 canister filter. It's a big version of the other Edens you might see around. It has the same slim profile, making it a good option for putting right up against the tank where space is tight.
There was another thing though. If you look at the top, there is a hole and a seal there. That is where you can stick a standard aquarium heater. The seal allows you to have the thermostat knob out and the water in the filter can circulate around the heat element. It looks like it would have no trouble fitting a 300W heater, so if you don't like all that extra hardware in the tank, there's another option to consider.
Here our hand model Chris demonstrates removal of the heater.
Just another option I thought was worth mentioning.
