New heater, varying temperatures?

[rachelled]

I just purchased a Marina Betta submersible heater (8w) for my 2 gallon tank. I placed it as shown in the little pamphlet it came from, near the top.

What I am noticing hours later is that, while it's quite warm in the top half of the tank (30 degrees according to the thermometer), it's cooler near the bottom - Enough that I could feel the difference when dipping my arm in.

I'm just wondering if that sort of divided temperature is normal or healthy for the fish to pass through different temperatures while swimming?

[Pasqua]

hmm, do you have a filter in the tank? If not, prehaps the water isn't circulating enough to spread the temperature around.

Are you possibly able to position it lower or anything?

I am not sure if bettas are ok with water of varying temps like this but if it is enough of a difference that you can feel it with your hand then it certainly isn't ideal.

[rachelled]

I don't have a filter... Well I do, but when I put it in it seemed too harsh for him, he looked like he was being sucked in! The filter holes aren't big enough to be harmful I don't think, but I took it out just in case.

I positioned the heater closer to the middle, here's hoping that works!