I'll be getting a new Betta tank soon, a 25 litre Superfish. I've always used 25w heaters in nano sized tanks before, but as I like to keep my Betta tanks at 28c I've been thinking of getting a 50 watt.
I've tried most heaters over the years and loved the Fluval Edge for my Chi tank, but could never get the temperature to go above 24 which was OK for the fish I had with it but not for a Betta. I always think the Visi Therm and Hydor Thero are a bit big and chunky for a small tank but have been looking at the Eheim Jager which, although long seems quite a neat heater, or, if I'm going for a 50w, should I go for the Fluval E50? I've got a E100 in my AR620 tank and its been great, but the Jager comes with a 3 year guarantee which does impress me.
Both these heaters are around 9" long, which should be OK with a black background.
I'd be grateful for opinions