Aquarium Digital Temperature Controller




A more accurate and safer way to control your aquariums temperature. Most controllers on the market are expensive, unreliable, and can only control either a cooler or heater not both. You can make this for as little as 16 dollars if you already have everything you need. Or around 40 if you need to buy everything. This could also savs your tank from a pump failure if you keep your heater in the sump. *Be aware this is high voltage , BE CAREFUL I'M NOT RELIABLE FOR YOUR MISTAKES OR INJURY.

Step 1: Parts

1. Controller
There's a very large selection you can buy on Amazon. Most of them are good quality. I went with the inkbird ITC 2000 because it has two alarms as well as one being a relay meaning you can put your own alarm in. The ITC 1000 has two relays and one built in alarm. Keep in mind if you need cooling and heating you must buy the 1000 or the leerway.

^(this model is in Celsius only)^

^(for heater+cooler, only one Alarm) ^

^(one I bought. Heat only. two alarms)^

2. A old(or new) lead chord. From this you can take the male plug and the color coded wires with in.

3. A female socket. I'm using the other end of the lead cord however if you want your outlets to be right in your box like a wall socket then you must buy that and a cover.

4. A box. You can buy a radio shack project box, a clear plastic one. I bought a grey junction box. About 11 dollars. A project box is about 7 dollars.The junction box is harder to cut through. (YOU MUST HAVE A JIGSAW! It must be 4 inches deep at least and however large you need it for your outlets.

5. Either a solder iron or wire connectors.

6. A alarm this is optional. As are my LED lights I'll use to know my heater is on and the unit.I bought a red buzzer light on Amazon and I plan on programming mine so it'll go off if the tempature drops too low. However the unit has a built in alarm system.

7. Dremel, drill, file, cutting tools, screw driver wire strippers .

Step 2: Drill

1. Drill the right size hole that'll fit your lead chord. Two holes total.

Step 3: Plan and Cut

Plan everything. Use my circuit diagrams or build your own. Measure and draw out everything on your box and then cut. The box is 2 3/4 long and 1 2/15 high. Feel free to message me with issues or if you want me to make one for you. The green and orange lights are optional.

Step 4: Wire

This wiring is very simple. I used wire nuts however soldering could easily be done instead, make sure you use shrink wrap if you do. If you use a different model/want a outlet to be powered then your neutral line(white will go to the left side of the outlet(the bigger slot) and the hot(black) will go to the right. If you have cooling and heating(on a different model) then make sure you brake the bridge tab between the two hots on the outlet. If wiggled back and forth the metal will snap. First begin by removed the orange tabs on the sides and the plastic cover on the back of the device by the one screw. Insert all components and use a screw driver to lose each connection point in the unit. And fallow the diagram. The hot will be the line the unit will open and close, the neutral will always stay connected to the load or whatever is being powered.

Step 5: Check and Test

Check all the wires to make sure they're snug and won't come loose. Place the cover plate back on and hook it all back up and put the probe into the tank. If you're using a sump system I suggest having the probe as close to the surface of water as possible as once the probe hits the air it'll take the tempature of the air and set off the alarm incase of a pump failure. Keep in mind if the alarm sounds then the device closes all switches so make sure the set alarm tempature isn't too low as if it goes off then the tank will no longer heat. I suggest not plugging your heater into it right away just to make sure everything works okay with it.



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    8 Discussions


    Question 6 months ago on Introduction

    Hi there,

    Great wiring diagram, if I just want to run a fridge from the controller and do not need the lights included, would I just wire Hot from the voltage source (male end from the plug) to AC Power 1 and the cold from the voltage source to AC Power 2 and then on the loading side, would I just run hot from Load 2 to the voltage load (the female end of the plug) and cold from Load 1 to the voltage load. Also, I wasn't planning on wiring in an alarm, is this ok?



    8 months ago

    very cool!!


    3 years ago


    i would like to make the same,but need to install cooling system alone.what all changes should i have to make. can you please help me with the circuit

    2 replies

    Reply 3 years ago

    hi there, if you are just going to substitute a cooler in place for a heater then follow what I've done. The relay opens to a regular female outlet and that controller has both a cool and heat setting.


    3 years ago

    I would like to match the temperature of the water going into the aquarium to the temperature of the water already in the aquarium. I could use this system if I could figure out how the use the current temp in the aquarium as the system set-point. Do you have any ideas on how to do this?


    3 years ago

    Home made burning laser