Q: Do I need to get some type of heater for the winter for my fish? It doesn't get too cold here. Almost never below freezing. If so what kind of heater do you recommend?

Question submitted by Eric, Takatsuki - Japan

A: How tres cool, we just got our first question from Japan :)). Well Eric, welcome to the bettatalk.com family! Please have a seat in our classroom while I work my way to the blackboard. Topic of our class today: Heaters 101 :).

So today children, we are going to talk about heaters. Bettas and heaters, to be more specific. As you know bettas are tropical fish and need water temperatures in the range of 65F to 85F if they are to survive. Ideal range is 70F to 80F. From 60F to 65F the bettas will become more lethargic but they will still survive (grouchy but alive). Below 55F bettas will get hypothermia and die.

Please quiet in the back row!

;) OK, so as I was saying, for your bettas to truly flourish you will want the water temperatures to not drop below 60F. The main concern here is not so much how cold it is in your country/state etc, but how cold it gets in your home. The way I go about assessing if a tank needs a heater is with the help of a thermometer. I measure the water temps. If temps fall below 65F, I personally add a heater. 

Now kids, a very important note about heaters. Heaters cannot be used on tanks smaller than 5 gal. They definitely are not an option for jars, bowls or tiny tanks. Why? Because even the smaller heaters could turn your bettas into bouillabaisse (fish soup) in less time they it took me to type this (and I am a fast typist LOL). 

Mr. Betta says : "PLEASE don't turn me into soup!". 

So here are pointers about how to keep water in safe range for different set-ups:

  • jars, bowls or any tank below 5 gal: your best bet is to heat the room itself where the jars/bowls/small tanks are located. In my case, that would be my fishroom area. I have a stand alone heater (oil based, with thermostat) which I keep 'just in case'. So far I have never needed it because I live in Southern California, but if it ever came to this, my bettas would be cozy cause I could heat up the fishroom until the jar's water was once again above 60F. If your room is too big, or your heater not powerful enough, consider moving your fish to the bathroom and heat it. A bathroom is smaller and will take less time/energy to warm up.

  • tanks of 5 gal or above: Simply add a heater. But not just ANY heaters. You must chose a heater with a wattage that is suitable for your tank's size. For example a 10 gal tank could do with a 50W heater, while a 60 gal tank may need as much as 200W heater. Put too much wattage in too small of a tank and you could once again cook your fish (Mr. Betta says: "OH NO! NOT AGAIN!"). Put too little wattage in too large of a tank and your heater will not be able to bring the water temps up sufficiently. When you go to the store to purchase your heaters, read the labels. The label of each heater indicates what size tanks it is suitable for. Tip: Keep a glass top on your tank it will keep the heat in the tank and will cut down your electricity bill ;).

Picking a heater. Yes, I guess that kinda was your question in the first place he? Will the kid in the red shirt over there stop throwing chocolate-bar-wrappers-carefully-molded-into-deadly-balls at my forehead? Thank you.

  • regular heaters will hang on the inside towards the top of the tank and are the least expensive of heaters. They are also not the most reliable. Should the tanks' water level drop, the heater will no longer be in contact with the water (or at least not enough of it will be) and heater will overheat and crack. A cracked heater that turns on can be very dangerous to both your bettas and YOU. (Zaaaaaaaap)  

  • submersible heaters are more expensive but well worth the extra dough if you ask me. You can fully submerge them inside the tank because they are 100% water proof. No water can get inside them and so you could typically lay one down at the bottom of the tank if you wanted. This way when you do a water change, and if you forget to unplug the heater (which you should always do when working on a tank - unplug it that is) your heater will remain submerged because it is at the bottom (horizontal). As little as 1 inch of water would suffice to keep it happy. I used to get the cheaper normal heaters but all of them died one after the next and I also had two close calls (accidents) with them. Since then they have been banned from my fishroom. I currently ONLY use submersible heaters, and pick good brands.

Remember: Saving a few dollars on a heater purchase is NOT a good move because a faulty heater may KILL all your fish (as in cook them to death) or even electrocute you. So Faithyoda says: If peace of mind you want, spend the money you must.


OK kids, it's recess time! I hope this helped and Sayonara! :))