Finding the right temperature for a Betta fish in a 5 gallon aquarium

August 8, 2015 2:26 PM

Need help finding the right temperature for a Betta fish in a 5 gallon aquarium

Hey folks, I need a little wisdom if you have it. I've recently set up a new 5 gallon for a Betta on my desktop. The aquarium has a filter and it has a heater. I cycled it before adding the fish. My issue is with temperature regulation. When I added the fish, a red and white betta I named Maple because he looks like a Canadian flag, I moved over a few items from my other aquarium to help make 110% sure the beneficial bacteria would be present. The other aquarium is a 10 gallon with another betta and some tetras. I have successfully kept them alive for three years now, so I think I have a decent level of understanding with how to deal with small aquariums, that's why I decided I would be able to go ahead with a five gallon. One of the items I moved over was thermometer, and that's where I started encountering a problem. The two thermometers in the tank reported different numbers, and the third one I added was also different. I don't know what the temperature is in my tank. I tried to fiddle with the heater to find a real green zone area all the thermometers agreed on, but it seems like when I turn the heater on even a little bit all three say I'm overheating. I have since unplugged the heater, more than 24 hours ago. My thermostat for the house is set at 73, but the thermometers both show the temperate in the tank higher than that. One, a Zoo Med digital shows the temperature at 79.3. The other, a generic Pet Smart suction on the side is reading 78.

So, here are my questions for anybody with experience and wisdom on this:

1. What is the ideal temperature for a lone betta in a 5 gallon?
2. How the frig do I determine what the actual real temperature in my aquarium is?
3. Is there some reasonable explanation why multiple thermometers are showing the temperature as higher than the thermostat temperature in the room should be even with the heater unplugged?

I don't think any of these readings are outside of betta tolerance, but I kind of strive to make an effort to provide ideal conditions for my fish. I'm a vegetarian and believe in animal rights so I take seriously the idea that humans who keep pets have to do it very ethically.

So, do you have any advice for me on how to keep the right temperature in a 5 gallon?

This is the heater.

posted by Drinky Die to Pets & Animals (5 answers total)

I would use a cooking thermometer, preferably a quick-read or instant read. I just bought this and it's a champ so far - it'll also read the room air temperature, which I find useful. Or if you have a laser thermometer you can check the temp of your walls and the water surface.

I always kept mine 78ish, tried not to let it ever get below 76 or over 80 for too long.

You'll be getting some heat off the light, assuming there's a light.
posted by Lyn Never at 2:55 PM on August 8, 2015 [2 favorites]

Response by poster: I would use a cooking thermometer, preferably a quick-read or instant read. I just bought this and it's a champ so far - it'll also read the room air temperature

Thanks. The lights are LED, I've tried off and on for 12 hour periods and haven't seen any influence based on the thermometers I'm using. The aquarium is by a curtained window but I also haven't seen any night or day fluctuations. The thermometers give me different numbers but all give the same numbers in a pretty stable way. The Pet Smart thermometer is the one I had in the ten gallon and the fish there have done fine for years, but the fact that it is reading higher than the room is troubling me. If I can get the same thermometer to read the air and the water that would really help me feel more secure here.
posted by Drinky Die at 3:08 PM on August 8, 2015

Yeah, I would not trust cheap aquarium thermometers to be very accurate. Because they're cheap. They mainly just let you know if your water is dramatically too hot or too cool. I use a digital cooking thermometer to test my tank.
posted by gnutron at 5:11 PM on August 8, 2015 [1 favorite]

Response by poster: Anyone have a recommendation for a particular brand with a reputation for accuracy? I honestly was not aware this was something that a cheap option could not measure accurately.
posted by Drinky Die at 5:20 PM on August 8, 2015

Best answer: Thermapens are very reputable and accurate cooking thermometers, but they also are pricey at 96 bucks.

They also make a cheaper version called the thermopop at 30 bucks that will be perfect for this situation, since speed of readout (5 seconds vs 2 on the thermapen) and exact temperature to the 0.1 degree (vs 1 degree on thermopop) is not needed here for this Application.
posted by Karaage at 4:44 AM on August 9, 2015 [1 favorite]