help fast please

[Cerulean]

I am going to buy a heater for my 2.5 minibow tank tomorrow and i am not sure which one to get.I need some info from users please. I have the incandescent light which over the summer has been warming the water up to 8 degrees each day however in the night it drops and i live in a basement suite and as it cools off it will be more necessary to have a heater in it. I don't know which one to go with. A 7.5 watt or a 10 watt.
There is one by Auqean which made the tank,or by minibow i think and a few other ones meant for small tanks. Most as i can see are preset and aim to raise the temp about 8 degrees above ambient room temp, but i wonder how that works with the heat from the light and which ones you guys out there have the best luck with in this size of tank. Want to keep my little guy happy so please post quick guys. Thanks so much for the help.

[Aus]

I'n not sure what brands are cheapest or available where you are - but try to get an adjustable heater up to 25w (mine is 30w, for the 3.5 gallon) - if it's adjustable it will raise the temp to the preset (78F, say) and then shut off when it hits that temp. So way less risk of over- or under-heating, and really worth the few extra $ it might cost.

[Tikibirds]

I'm not a fan of the smaller wattage heaters. I would go with a 25 watt adjustible one. Hagen Eite's a pretty good. I have a misture of heaters I got off ebay or amazon.com since the local selection is lacking and pricy. I have a tetra preset 50 watt which should be able to heat up a 10 gallon tank to 78..it cant even keep a .5 gallon tank above 72

[Seki]

Look into the Hydor Theo heater. It's what I use in my 2.5 gallon and it works fantastically. Keep the temperature nice and steady.