Uneven Temp? Update, Please Help

[ellena]

So in my white betta tank I have started to notice the temp at the bottom is colder than on the surface. I measured it and it's 25C down to 23C although it felt way colder to my hand!
As it's a betta tank, I can't really increase flow to spread the hot water around can I? Any thoughts if this is a problem and how I can solve it?
Thanks

UPDATE
So, I've got a 100w heater and it's made no difference I set it to 28, it was 28 at the top 21 at the bottom. So I upped it to 30, it was 30 at the top, still 21 at the bottom
The tank is approx. 30cm cube. The heater is nearly 30cm long, so is set diagonally across the whole back wall of the tank. The filter is vertically above the bottom (hot end) of the heater. There is flow, but it is slow, for the betta.
I am presuming now that it is a flow issue, not heater strength? Although, I'd think 100w heater in 5 gall tank would keep it all toasty with no flow?
Any suggestions please?

 

[tom130691]

lower the heater?
and top will always be slightly warmer as heat rises

is you heater diagonal like its supposed to be?

 

[ellena]

Yes, heater is diagonal and goes from the water line almost to the sand, so I can't lower it any more.

 

[Lacuna]

I think bettas like slightly warmer temperatures, so I would set the heater to 27C then it should only drop to about 25C towards the bottom, and both of those temperatures should be okay for a betta. 23C sounds a bit cold for him.

 

[ellena]

I've got the heater set to its highest which is 32, but it's only getting to 25.

 

[theshadowinc]

I've got the heater set to its highest which is 32, but it's only getting to 25.

What wattage is your heater? for what size tank is it in?
What kind of heater is it? Does it have a built in protection that doesn't allow you to over temp the water means when temp reaches 72-78 it shuts it off automatically.
What are you measuring the temp with a digital thermometer?
2 degree difference from bottom to top of tank isn't a huge change to worry about

 

[fish_tank0311]

If it isnt already it should be sitting next to the filter so the filter blows out the water and regulates the heat distribution.

 

[ellena]

Heater is a 25W one in a 5 gall tank. I don't think it has a shutoff as the dial goes up to 32C. Measuring the temp with a cheap aquarium spirit thermometer.
It's diagonally across the back of the tank. The hot end is under the filter inlet. Thing is, the filter flow is so reduced for the betta, I don't think it's doing much distributing at all.

 

[theshadowinc]

Heater is a 25W one in a 5 gall tank. I don't think it has a shutoff as the dial goes up to 32C. Measuring the temp with a cheap aquarium spirit thermometer.
It's diagonally across the back of the tank. The hot end is under the filter inlet. Thing is, the filter flow is so reduced for the betta, I don't think it's doing much distributing at all.

Up the flow a little bit more, no need to have it reduced to the point of no distribution, just because its a betta doesn't mean you should reduce the flow, you still need to keep the flow rate up not only so it stays cycled but so you have even distribution of the temp. 25w isn't enough for your size tank especially if it winter where you are you would need a 50w heater for a tank that size, depends on your room temp as well, all the thermostates on heaters are set at 72 room temp so guessing you maybe at 68 for you house temp this will differ the resaults when using a 25w heater, up the flow see if that works if it doesn't and you are still concerned go with a bigger heater.

are you using hang on back filter? If you are you need the heater in the area of flow, since its a 5 gal tank set the heater vertical and near the bottom and away from the flow this might help in increasing the temp throughout the aquarium. Try these things first and see what happens before getting anther heater.

 

[ellena]

It's an internal canister filter, not HOB. When you say thermostat set at 72 room temp, do you mean my house heating thermostat? I don't have one, but my house is cold. I had a tank in the kitchen where it gets down to 10C in the winter, so I bought a 100w heater which has coped very well, keeping the tank at a steady 27C. So I think I'm going to get another.
Regarding increasing the flow, not sure how to do that? I have put a bit of sponge over the outlet and that's either on or off, so the flow is either nothing or raging! There's no setting on the filter itself. It's a fluval mini.

 

[silverrabbit]

Maybe putting in an airstone under the heater would help to circulate the water better? Also, maybe point the outflow of the filter to the back of the tank, so it hits the glass and disperses around the heater... that way you can have it on a higher setting but hopefully the flow won't bother the fish

 

[ellena]

It doesn't have a directable outflow either Thanks for the suggestion though.

 

[silverrabbit]

Aww no, shame

Hope you get a solution

 

[loraxchick]

honestly, id look into getting a new heater. perhaps the same you have now if the one you have is old. they tend to be sort of unreliable after a time, especially the smaller ones.
cheers

 

[theshadowinc]

honestly, id look into getting a new heater. perhaps the same you have now if the one you have is old. they tend to be sort of unreliable after a time, especially the smaller ones.
cheers

Heaters are just umm.... finaky or is that finakie lol....