heater for 2.5 G nano

[Horizon Canopy]

what is a good heater to use on a 2.5G nano? I was planning on using a 50W Ebo-Jager that I had laying around, but its much too big... TIA

 

[Dakafall]

i'm just usin' a small 50w tronic on mine

 

[DRC69]

Same unit I use. I will also use it on my new 24 aquapod setup.