Best digital Aquarium thermometer that actually works. Plus overheating protection. $24

[Oughtsix]

I am guessing that like me many of you have tried various of the cheap digital aquarium thermometers and have found them to be little more than random number generators. The analog blub thermometers are supposed to be quite accurate but my old eyes have a very hard time reading them and an even harder time getting an accurate reading without parallax error.

I am setting up a 180g tank and would like to know what the actual temperature is without pulling out my multimeter and thermocouple to get a reading. After looking at several options for "real" thermometers which ranged from cheesy to ultra accurate scientific grade equipment I finally decided on this Inkbird temperature controller for $24:
https://www.amazon.com/dp/B07KC24CK...jbGlja1JlZGlyZWN0JmRvTm90TG9nQ2xpY2s9dHJ1ZQ==

All the reviews say these Inkbirds are quite accurate at measuring and displaying temperature with the added bonus of cutting power to my heaters should one get stuck on and try to boil my tank. $24 for an accurate digital thermometer plus some added heater insurance just seemed like too good of a deal to pass up!

They also make a version that will send the temperature to your smart phone via WiFi for only $40: https://www.amazon.com/gp/product/B07PVBG8K1/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

These prices I am quoting both reflect current Amazon click to use online 20% off coupons. Someone that has considered getting a temperature controller in the past might find this 20% off the motivation they need to finally purchase one.

I hope that this temperature controller works out as well as all the reviews say it should!

 

[Rocksor]

It's not completely accurate, but good enough. I've run 2 inkbirds in the same tank and in the same spot, showing a difference of 0.5-0.8F between each other.

 

[BigDaddyMagnum]

i run inkbirds myself, while not completely accurate you can change the difference to get it pretty accurate

 

[FJB]

I guess you are talking about two different things- A 'good-enough' (satisfying) thermometer, and a temperature controller.
I can not say anything about controllers as I have not own one.
Regarding thermometers, I have been very happy with a point-'n-shoot digital thermometer I bought 3 years ago at Harbor Freight Tools (photos below). It was under 20 bucks, perhaps substantially less. I find that is accurate enough (consistently gives me 2 degrees F above what I can read with submersible glass thermometer), and it is very precise (always is off by those 2 degrees, no more, no less). To me, that is absolutely perfectly good. In fact, its readings compare well with a medical one my wife keeps at home.
I use it to read aquarium temps, change water temps, fish bag temps, etc. Just point and read, in Celsius or Farenheit. I think I have changed the battery only twice in 3 years. Cant ask for better.

 

[jim barry]

I have used these and they stuck on. First time I caught it and fixed it by moving the heaters around. Thought no more of it, then 2 months later they stuck on again and killed some of my fish!
May not have been the exact same make but looked exactly like this. Maybe I had a cheap Chinese import or something. But they were cheap. I wouldn't trust them again.
I now use the titanium aqua medic which are very good although the instructions are crap!

 

[FESHMAN]

I've been using multiple inkbirds (prewired ones) for 3+ years with no issues so far. The temperature reading might vary a bit but I consider it acceptable and it can be calibrated.

Now I'm using a few stc-1000's (also inkbird) for over a year and so far no problems. These also have an alarm feature with a really loud buzzer, but their only downside is that you have to do the wiring (it's really simple and the instructions are clear). You can also fit it on the stand after you make a hole for it so the temperature reading is always on display. or you can fit it in a project box

 

[Rocksor]

If your heater is working fine and the controller stays stuck on, then the heater will turn off on its set temperature. I set the heater temperature to turn off about 1 or 2 degrees above the setting on the controller. So you have 2 areas for failure points.

If your fish are fried then both the controller and the heater were already not working properly. Every year before it gets really cold in the room, you need to check the heater to make sure it is not broken and stuck on. Don't use a broken heater with a heater controller. Replace the broken heater.

 

[Oughtsix]

I have a 200watt Eheim heater which I don't think will be enough for my 180G tank. I am seriously considering buying a 300w Eheim preset temperature heater. The Eheim preset is permanently set to 77 degrees F = 25 degrees C. The preset is supposed to be more reliable because it doesn't have the temperature adjustment which is where problems tend to happen. I am thinking I can use the Inkbird temperature controller to set any temperature UP TO 77 degrees. If the Temperature controller gets stuck "ON" the heater itself should never go above 77 degrees.

My only question is will I ever need to run the water temp above 77 degrees on an ongoing basis? If I need to heat the tank to treat the fish I can easily throw in a spare heater for a few days. But if I want my tank running above 77 on an ongoing basis the preset heaters would not work. The only thing I can think of is Discus like warm water. But most of my plants do not like Discus temperatures from what I can tell.

To me the most likely cause of an Inkbird controller failure is if the temperature sensor probe gets removed from the tank/sump.

P.S. I opened this thread mainly because I searched all over the internet for a reliable digital aquarium thermometer and all the suggestions were to use an analog glass thermometer because all the digital ones were useless. I have one digital thermometer that is off by 12 degrees F. If the Inkbird that is on its way will accurately read within 1 or 2 degrees of actual temp I will be very happy. I don't think I can really get much better than that without going to an expensive scientific thermometer that would need professional calibration.

 

[TheWolfman]

I use that same controller. It's been running on my tank for 3 plus years. Works very well and is extremely accurate. You can calibrate it to get it within a half of a degree if I remember correctly. I checked it a few times over the years, and it hasn't changed. I agree about making sure your using good working condition heaters, and checking them once a year.

 

[TheWolfman]

I also wanted to add I used 2 300 watt eheims on my 220. They worked well with the inkbird controller. I kept the tank at 82.