Is it True Betas dont need a filter

I try and take the best care of my fish possible. I have always belived in the "Every Fish Needs a Filter" rule because every fish needs clean water. So I'm setting up a Beta tank and I picked up a 3.5 gallon rectangular aquarium. When asking in my local fish store (Whose opinions I have always trusted and respected) about a suitable filter they said that I did'nt need one and that betas hated the water movement.

Is this true? I hope to maybe keep an African Dwarf Frog as well would they benifit from a filter as well?

ZooTycoon and Evelyn"B" are both right on with their answers. Bettas are tropical fish from southeast Asia and need temps in the range of 78-82.

Whoever told you, at the LFS, that bettas hate water movement, obviously hasn't kept bettas. Bettas are OK with water movement as long as it doesn't cause them to be moved around the tank with it. They come from quiet waters where there is some movement but not a current that disturbs them.

ADF's are great companions for bettas. A 3.5 g tank will be OK, but a 10 gallon would be better if you have the room. If you can return the 3.5 g tank and get a 10 g, that would be the best idea. The wattage formula for a heater is 3-5 watts per gallon. I don't think they make one smaller than a 25 watt, but I may be wrong.

You are entirely correct in the "every fish needs a filter" rule. Some of the bigger, dirtier ones need two. Also don't forget to do your weekly partial (25-30%) water changes no matter what size tank you have.