I've been heater shopping and I am debating between a 25 watt Hydor Theo and a 50 watt regular Aqueon (since they don't make a 25 watt) adjustable heaters...from what I have read the 50 watt AquaTop and Cascade heaters are not that reliable.
It's for a 3 gallon aquarium, and it will probably have to deal typically with room temps in the low to mid 60's much of the time. Some people seem to think a 50 watt can be used in smaller tanks (below 5 gallon), but I am a bit worried. One pet store employee told me it would fry my fish (of course, he said that about the 25 watt also).
It seems to me that the reviews for the Theo are overall better than the Aqueon, but the Theo is nearly twice as expensive (it's about $30 at the LFS and the Aqueon is about $17).
What do you all think would be best?