what wattage ?

[Pauly]

What is the best wattage eheim heater for a 250ltr tank ?

[samir]

i'd say about 300 watts should be more than enough, less if it doesn't get too cold where you are. A good quality 200 watt would probably do the job as well.

[mcloughlin2]

Go the 300w!

I have one on my 220L tank ... Its hardly ever on, so saves on electricity!

[nicholas76]

300 watt easy