# Are those "always on" mini heaters a bad idea?



## ironklad

Right now, my ~2G betta tank has one of those mini heaters that is a flat thin black plastic rectangle with no thermostat - it's just always on. I would prefer a heater with a thermostat, but it seems like all the heaters I've found that are rated for <10 tanks are of this variety. The tank usually stays around 78-80F, but I'm concerned that my house will get warm this summer, and the heater will overheat the tank. Has this been a problem for anyone? Thanks.


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## coralbandit

although there aren't many choices for small tiny heaters and even less for affordable ones ,the pre set ones are not all that great.They may work(if even only for a while) or they may not.Often the temp of the room the aquarium is in dictates the true wattage needed.And many have found that no matter where they set their heater at it is never the actual temp reached in the aquarium.Being able to adjust the heater can make a cheap heater work better for your particular needs.


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## rtmaston

most of the small heater are preset.i got one for my 5 gallon and so far is working ok.i keep a close eye on the temp to make sure it stays 78


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## ironklad

Hmm. I try to save energy by not running my house heater or AC too much, so the house temperature varies quite a lot. If I'm not home to run the heat or AC, the room this tank is in varies from low 60s(F) in the winter to high 70s(F) in the summer.

@rtmaston are you saying that a "preset" heater does have a thermostat to turn itself on and off (but you can't manually set the thermostat)? Or are they literally "always on"?


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## coralbandit

my aqueon chart says a 50w heater can heat a 5 gallon tank 15 degrees above room temp based on room temp of 68-72.It (50w)is still effective on a 10 gallon up to 10 degrees above room temp,but to get a 10g up 15 degrees above room temp calls for a 100w.


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## Avraptorhal

ironklad said:


> Hmm. I try to save energy by not running my house heater or AC too much, so the house temperature varies quite a lot. If I'm not home to run the heat or AC, the room this tank is in varies from low 60s(F) in the winter to high 70s(F) in the summer.
> 
> @rtmaston are you saying that a "preset" heater does have a thermostat to turn itself on and off (but you can't manually set the thermostat)? Or are they literally "always on"?


My .02. If the goal of tank husbandry is keeping everything as constant as possible, then a preset heater is not what you want. Those heaters DO NOT have a thermostat so they are always on producing heat in the tank raising the temperature above room temp. If your room temp varies the tank temp varies as much as the room.

The wattage rating of the heater is a measure of how fast the tank temperature will come to the desired temp. As long as the thermostat in the heater is set at a temp the temp in the tank will conform to that provided the heater is large enough for the size of the tank. Just as the thermostat in your house will maintain a constant temp provided the house heater is the correct size for the house. Which is the way of saying that there is no max heater rating for any size tank, but there is a minimum size determined by the size of the tank, the room temp and the desired temp of the tank for the fish in it. The max heater size is determined by your pocketbook, ie, cost.
. 
Sorry for the encyclopedia, but I felt that the technical info needed updating.


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## catfisherpro

The preset heaters are fine for small tank 15g an under bigger tanks are better with adjustable. That's how I use them never really had any probs but when I first started this hobby yrs ago I tried some preset ones in my 50g it was horrible the temp was always to low it was preset at 75-78f but would only keep the water anywhere from 65-67f so figured it was work took it back bought another one bigger same thing. But tryed them in 15g worked fine kept water 76-79f


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## rtmaston

ive have a small heater which is preset to 78.it does goes on and off with a red light that comes on when it heating.it saids that it will work on 2 gallon to 15 gallon tank.i have it on a 2 gallon tank and a 5 gallon and does do a good job.how long it will last I don't know.it does have I think a 2 year warranty.


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## Avraptorhal

I think that Tetra makes a tubular heater that has a preset thermostat in it. As you guys have said it works fine for a small tank.*i/a*


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## ironklad

Update - I ended up getting this heater. It says that it has a thermostat that maintains at 78 +/- 2 degrees F, which should be perfect. I agree with exactly what Avraptorhal says; an "always on" heater is going to make the tank "room temperature + 5 degrees" (or whatever). My house temp fluctuates a lot, so this was a big concern for me. 

Tetra Submersible Aquarium Heaters - Fish Tank Water Heater and Aquarium Water Heater from petco.com

It will be used in this tank which I got today. BTW this is a great deal at $60. I've seen this around $100 in store before.

Aqueon® Evolve 8™ nano All-Inclusive Desktop Aquarium with LED - Sale - Fish - PetSmart


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## chipmunk1210

The "pre set" heaters like the one you are purchasing/have purchased is a decent heater for a betta although I will recommend you get one that you can adjust the temperature that would work in your tank as well. The reason behind this is if you needed to treat your betta for something -- water of 82F-84F is the best temp to promote healing of most injuries and getting a pre set heater to that temp is impossible. I use those pre sets in most of my smaller tanks but the species in them do not need as warm of a constant temperature that betta require. I do have one on my divided betta splenden tank but my house does not vary in temp very much so the temp in the tank does not vary either so it works nicely. With your home having a decent temperature fluxuation like you said -- pay close attention to the temp in your tank with the pre set.


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## ironklad

Thanks. I've had the new heater in my tank for a couple days, and it seems to hover around 75 degrees. I would have preferred it to be a bit warmer, but the stability was my main concern.


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## chipmunk1210

I will say with it only getting up to 75F, you really should look into getting an adjustable one that will push your temp to 78F at least. Your betta will live at the constant temp of 75F so you don't have to rush out and spend more money right away. The main problem with cooler temps is that they are not as active which leads to fatty tissue build up around the organs. Just some FYI for ya. I can't wait to see pics of your tank with your betta in it once set up.


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## ironklad

So, say I get a heater that's rated for a larger tank, but has the adjustable thermostat. That should be perfectly fine right? Even though it has a higher power, it's still going to turn itself off when the water gets warm enough... 

Oh yeah, and I got the Aqueon 8 for him, will get it going soon


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## catfisherpro

Yes it will shut off when temp is reached


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## ironklad

That's what I figured... the guy at the fish store said it would be too powerful, guess he doesn't know what he's talking about.


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## catfisherpro

Alot of them dont they try to just sell not caring if it works for u. At my lfs we all no about the animals we care for


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