Cobalt Mini Heater

[VJM]

I ran all over today picking up everything I think I need for a Betta. Pretty happy with everything, except the heat situation.

The rescue craigslist Betta I have my eye on comes in a 2.5g tank. It is actually chilly in southern Florida right now (ok,ok. It's 56). Obviously, I need a decent heater. My house thermostat says 70, so I just need 8-10 degrees.

Both Petsmart and Petco had terrible heater selections, so I bit the bullet and drove 45 minutes to the great LFS. Their recommendation was not a 25w heater, but a mini Cobalt preprogrammed heater. I was super dubious, but he assured me it was legit for a 2.5g.

I got home, put 2.5g in a bucket, and put the heater in. In 4 hours, it has gone from 70 to 72.

What gives? If I put in enough warm water to get it to 78, will it be able to keep it there? I ordered one of the following online, just in case I return the Cobalt.
http://www.adana-usa.com/index.php?m...roducts_id=686

[waterdog]

Most of us, either through experiance or good advise, use adjustable heaters. Those preset things IMO are useless. I had one that wouldn't turn off and almost boiled a betta. They just aren't worth the risk.

[Crowntails]

I'd return it for a better adjustable heater.

[VJM]

I checked it this morning: 68 degrees. Weak sauce. It's going back.

I also ordered a Hydor Theo rush from Amazon, and I have the Archaea 25w arriving as well.

Given that no one in South Florida seems to stock 25w adjustable heaters, I will be glad to have a backup.