What Size Heater For A 15L Fry Tank?

[orangefish]

I have a 15L fry tank with guppys and platys in at the moment, and it currently has no heater. However, I realise I should get one for it- especially as I may breed cichlids in the future.
What size heater would people recommend for this size tank? What brands would people recommend? Where is the cheapest place to buy this sized heater? Any help appreciated, thanks.



I have found this- the Newattino 10W heater, which says it's for aquariums between 10-20L. Does this look like the right one and a cheap price? http/www.aquatics-online.co.uk/addtobasket.asp?skid=4201

 

[TimNorwich]

I have a 17L tank, with a 25W heater, which works perfectly with my tank. I can't see 2L difference being a huge issue. A lot of the time it seems my tank is heated by the room anyway as its such a small tank.