problem with the heating of the tank

[SharkyTheBetta]

I was using a 50W heater in a 5.5g tank and it was ok for my betta during the autumn period when the room temperature was about 76. During the winter time when the air temperature of the room decreased to a value of about 67 or 68 I have notice that at the bottom of the tank water was much colder (73) than at the surface (79) while the heater was adjusted for 79 and no matter in which position it was, vertical or horizontal. What should I do? Should I buy a small filter in order to allow the water to flow? Or maybe an air pump? I am very confused. I don't want to create a too strong flow for my betta. I know that warm water goes to the top, but isn't it any solution to this problem without using a filter or something like that? I'll ruin every bubble nest this way...

This tank was used for a betta that developed dropsy (I think it was caused by these extreme temperature fluctuations ), I sanitized it a few days ago and now I am planning to move another betta in it and I want him to be happy and healthy. What should I do?

[Fishybitty]

I have two of these filters. http://www.walmart.com/ip/Regent-For...-1-ct/10313136

You can adjust the intake tube to reduce the flow to almost nothing. It will not mess up his bubble nest :)

[Kim]

I would add a filter...also, since it's a 5 gallon, you could do a fishless cycle before you add the fish, which will save you some water changes in the future :)

I had the same problem (darn this cold climate!). To solve it, I would position the filter intake tube right next to the heater. This keeps a constant flow of water around the filter and prevents the heater from just heating up the water in its immediate vicinity and turning off.

[SharkyTheBetta]

Thank you very much for your replies. I am going to buy a filter today and start cycling the tank. Hope betta will enjoy his new home soon.

[AyalaCookiejar]

Place the heater horizontally under the filter. This was my solution to the same problem :)