I have purchased two of the SmartThings water leak sensors. They work well and report temperature. According to THIS they are waterproof. Not sure how the communication would be underwater. But it may be an easy option for you.
RF (Zigbee, zwave, WiFi, Bluetooth, etc) is greatly effected by water. If you decide to submerge you will want to add a repeating device (mains powered device except some light bulbs) very near by for consistent communication.
Check out the following thread for someone who uses a contact sensor that has temp sensor in it. They added the probe for getting temp data. This would allow you to have the sensor on the outside of the aquarium and submerge probe for testing temp.
Quibino makes a device with remote temperature sensor. But if it’s a salt water aquarium, you’ll want to protect any device very well.
Tested my SmartThings water leak sensor in water. It was about 75 feet from the hub and continued to work. It provided water temperature changes as I added hot water. HOWEVER, I did not realize that my sensor is not the waterproof kind and I flooded it. It’s drying now…OOPS!
mmmm that’s good - lithium ion tea
nobody gets enough lithium from their diet nowadays
I don’t think any of the ST sensors are water proof, maybe resistant.
ha! what’s funny is the text says the new model (the one in your picture) but the pic on the website is the old model.
Received a private message from Aaron with this request. Not sure what that means…
He probably needs a support ticket to fix their website.
Good call. I did not even think about that.
Hey everyone, thank for all for replying. I can’t help but say I am till blown away at how complex this issue is. I just can’t believe someone has not made a sensor with and external temperature prob of some sort. I was very hopeful when I saw the ST sensor was water proof, but now it seems it’s not and I’m back at square one. Well I can’t wait to see what more of you have to say.
Thanks again, keep the ideas coming.
I have posted a solution in this thread, a sensor with an external temp probe…
Fibaro contact (door) sensor supports external temperature probe. This sensor is costly, though.
That sensor can no longer be bought (it’s been discontinued) and I can’t even find an old one on ebay, and the second version does not support the external probe.
Your correct, I just finished reading the thread you posted. It starts off talking about withing the same contact sensor I see all over the place that’s discontinued, but reading deeper I did see something new. I noticed the use of a Sonoff and a probe.
Sonoff TH16 Temperature and Humidity Monitoring WiFi Smart Switch and the Sonoff Waterproof Temperature Sensor DS18B20
I just ordered these and can’t even wait to try them.
All of the qubino modules allow an external temperature probe to be added
If you are handy with electronics check out this thread [RELEASE] ST_Anything v2.9.2 - Arduino/ESP8266/ESP32 to ST via ThingShield, Ethernet, or WiFi Easy to put together the NodeMCU and DS18B20 waterproof temperature sensor. Works great with SmartThings. You could even add an ultrasonic sensor to monitor water level. Here is a picture of one I made with connections for three temperature sensors