Can You Heat A Small Tank?

[lynn.12]

Hey everyone,

Thanks for maintaining a forum for beginner help requests, much appreciated!!

Anyways, I have a betta in a 5 gallon tank and no other fish. Tank is filtered but not heated and water is remineralized RO. I’ve had this going about 6 months but much of that was summer and we don’t use AC. I live in southern california so the winter isn’t very brutal, but it’s definitely been rather cold some recent mornings and I’m realizing the betta would likely appreciate some warmth. So far he remains very hungry and active but I ordered a Tetra HT20 50W heater with the intention of adding it to my setup. However in the meantime I’ve come across some horror stories online of people cooking their fish by trying to heat small setups..

So my question is, is it worth heating the tank, or will I risk stressing him out more with temperature spikes?

Any insight appreciated. Thank you!!

 

[AquaticJ]

Unless his tank is consistently 78-80 degrees, you need a heater. For every horror story there’s thousands of happy fish. Heaters can cook even big tanks.

 

[lynn.12]

Ok thanks, tank is definitely not that warm right now.. I’ll add the heater but do I need to be concerned about stressing him out as I bring up the temp?

note— I picked the heater out because of good reviews but also it only controls to 78 degrees, I can’t work up the temp gradually. Not opposed to getting a different one though if I have to.

I’m about to leave for a week so if this is something potentially very stressful I may push it til I get back

 

[FlipFlopFishFlake]

The temp should gradually raise as the heater increases the water temperature, your betta should be fine.

 

[FiscCyning]

Ideally you would raise the temp slowly over several hours. Does that heater let you adjust the temp or is it preset?

Edit: just saw you posted while I was typing. Even without an adjustable dial, you should be fine. It will still take the heater some time to get the water up to 78.

 

[lynn.12]

Ok awesome. Thanks so much for all the quick feedback. In retrospect it’s a little idiotic that I’d be more scared of temp fluctuation or heater malfunction than I would be of maintaining water at a totally unhealthy temperature.. but luckily he’s a trooper so far and I’ll get that heater in tomorrow

 

[AquaticJ]

A 50 watt heater that’s preset will probably make it too hot honestly. There are many factors but I’d recommend an adjustable one. A 50 watt heater won’t take more than a few hours to ramp up the heat in a 5 gallon.

 

[lynn.12]

Any recommendations on type then? I can monitor the thermometer for a couple days if this is like kinda a worry, but if it’s a major worry i’ll just get a new one

 

[Wraithen]

A 50 watt heater that’s preset will probably make it too hot honestly. There are many factors but I’d recommend an adjustable one. A 50 watt heater won’t take more than a few hours to ramp up the heat in a 5 gallon.

Is that first statement based on anything? Ive used 50 watt heater and they turn off when the water contacting them reached 77.8 degrees. How would the heater overheat the tank when it shuts itself off at its preset temp?

 

[VSA]

Any recommendations on type then? I can monitor the thermometer for a couple days if this is like kinda a worry, but if it’s a major worry i’ll just get a new one

I have been using one of these:

Was more expensive then the rest but has a wide range of settings and is easy to hide. Has been reliable for me since I got it in October.

 

[SuperMon]

Not to scare you, but I had that heater at one point and it exploded . . .at the very least the clear part broke apart in my tank, but no fish causalities. I just vacuumed the shards and upgraded brands. If i remember correctly the heater turns on as needed, once it hits 78 it turns off, turns back on once it drops a few degrees so you're going to have some flux.

Personally if my house temp is 75+ I check the fish tank temp and turn on a heater if needed. Currently my outside is freezing, my house temp is set for 75 and my tank is holding a 79 temp no internal heater, but my tank is near our house heat vent. If the heater still worries you, just move the tank maybe to a warmer room in your house ie. kitchen, living room. So either use the heater sparingly (because I used 50 watts for my 10 gallon when I lived in socal and it took under 2 hours to heat and hold temp for hours after turn off) or keep a warmer house temp

 

[Fanatic]

Hi Lynn12,

You can use a preset heater, but a lot of people prefer to use adjustable because it can heat a wide range of temperature.
My favorite heaters are adjustable, only because it's very easy to use them, and they give a clear warning when they are turning on or off.

 

[THRESHER]

I got one of these in my 20g with a single Dragon Goby. Keeps the temp between 78-80. Comes on when it needs to and shuts off when temp is reached.

 

[AquaticJ]

Is that first statement based on anything? Ive used 50 watt heater and they turn off when the water contacting them reached 77.8 degrees. How would the heater overheat the tank when it shuts itself off at its preset temp?

A lot of preset heaters are meant for specific volumes of water, so they’re designed to turn off and on a specific amount to treat said volume of water. I’ve tested this with my preset heater in my 55, it gets the 55 to 77, but when I put it in the 10 gallon it went to 83.

 

[Wraithen]

A lot of preset heaters are meant for specific volumes of water, so they’re designed to turn off and on a specific amount to treat said volume of water. I’ve tested this with my preset heater in my 55, it gets the 55 to 77, but when I put it in the 10 gallon it went to 83.

If thats true its a terrible idea from the manufacturer. How would they know what room the heater is in? They would cook a tank in an 80 degree room and freeze one in a 65 degree room. While I wouldnt doubt a 50w heater being unable to heat a 55 gallon, idk why it would run so hot in a 10. Possible mis calibrated heater?

 

[AquaticJ]

If thats true its a terrible idea from the manufacturer. How would they know what room the heater is in? They would cook a tank in an 80 degree room and freeze one in a 65 degree room. While I wouldnt doubt a 50w heater being unable to heat a 55 gallon, idk why it would run so hot in a 10. Possible mis calibrated heater?

My heater is more than 50w, but I was just giving an example of putting it in a smaller tank. 50w is about double the wattage needed for a 5 gal.

 

[Marzahtha]

The preset heater will be fine for a Betta. It's preset to 78 degrees. My tank usually sits around 77.8 I use the HT10 in my 5.5 gallon tank where I have guppy fry. It's smaller and fits better.

 

[mattgirl]

The only tank I use a small preset heater in is my 2.5 gallon snail jar. I don't remember the wattage in it. I bought 2 of them well over 15 years ago. I am thinking they are at least 50 watt though. I do know it wouldn't warm up my 10 gallon tank so I bought a 100 watt adjustable for it.

The 5.5, 10 and 55 all have adjustable heaters. The 5.5 and 10 have 100 watt heaters and the 55 has a 200 watt heater. It gets fairly cool in here at night but the heaters hold the tanks temps right at 76 at all times. i

What ever you do don't just set and forget. I've yet to get a heater that I can rely on the dial. What I do is set the dial just under the temp I want the tank to be. If it turns off before the thermometer tells me the water temp is where I want it I turn it up just a tiny bit. I keep doing this until I am sure it is going to hold the temp I need it to be. I continue checking it against the thermometer over several days.

I also keep a thermometer in the tank at all times and check it often to make sure the heater is doing its job.

 

[DarkOne]

A lot of preset heaters are meant for specific volumes of water, so they’re designed to turn off and on a specific amount to treat said volume of water. I’ve tested this with my preset heater in my 55, it gets the 55 to 77, but when I put it in the 10 gallon it went to 83.

You had a faulty heater. That is not how heaters work at all. I have a Tetra HT10 preset in a Fluval Spec 3 (2.6g) and it stays at 78°F. I have another HT10 in a 5.5g and it also maintains 78°F.

 

[HelloKittyPowa]

@lynn.12 I have the same exact heater for my 5 gallon as well and I definitely do recommend it. It has the temp adjust to 78 which is perfect for a betta. I had it since October of this year and it works great, it does not overheat. Only advice I would give is... Which I am sure other fish owners do, is unplug it when you are doing water changes. A submersible aquarium heater which you are getting, should always be unplugged when performing a water change for 2 main reasons. First, if you leave your heater on and expose it to air, it can overheat. Secondly, when the hot glass comes back into contact with cool water, the heater may crack from the sudden temperature change.