How to use a Temperature controller

[Fish Tank Travis]

Ok, excuse me if I'm asking obvious questions, but I'm fairly new to the hobby (just over 2 years) and want to make sure I avoid any stupid mistakes. I've made most of the noobie mistakes and only in the last 9 months have I reached a place where all my tanks are stable, colourful, free from fatalities and disasters, and providing stress free enjoyment for both the fish and my family!
I travel frequently on business. I have people at home who will throw the food into each tank on a daily basis, and my trips are short enough to allow me to do water changes when I get home. I do get paranoid sometimes wondering if a piece of equipment will fail while I'm away. For that reason I run 2 filters on each tank.
Obviously heaters can fail in two ways. They can get stuck on - cooking the fish. So it looks as if the temperature controller is the solution to that danger. The other problem is if a heater just gives up the ghost altogether. I live in a cold climate, so the fish would then die of cold. So if I were to put two heaters in each tank in conjunction with a temperature controller, would that work? I'm thinking that way, if one heater dies, the other keeps going - so I would be covered both ways. Is my thinking ok here? Or is there something else I'm missing?

Yes, that will work. The Inkbird controller has the capability to have a high and a low alarm. You can use the low alarm so that if the heater fails off, an alarm will sound if the temp drops a few degrees. Then, you, or someone else, can swap the heater out before the water gets too cold.

 

[aldiaz33]

Placement of the sensor is important.

You want to place the sensor in the same body of water as where the heaters are located to avoid a situation where water is not moving due to a pump stopping/failing. If the sensor is in your display tank and heaters are in your sump and flow stops, the sensor will be calling for heat, which could result in your heaters boiling your sump (if you are using standard aquarium heaters with an internal thermostat, as mentioned previously in this thread, this will help prevent that situation, but if you are using standard heating elements without an internal thermostat, this is a real concern).

I like to place my sensor where water enters my sump. My heaters are located right next to my return pump. This way the sensor is detecting water draining from my display and not getting a potentially false reading by placing the sensor too close to the heaters themselves.

Also, after determining the best location for your sensor, make sure it is secured in place with no risk of being pushed out or being inadvertently removed from the water. If the sensor gets bumped out of the water and begins detecting air temps, more often than not, those air temps are going to be lower than your desired water temp, so that could also spell disaster. Redundancy/fail safes to the extent practical are lifesavers.

Here's a good read in case you are interested.

https://www.jehmco.com/html/temperature_controller.html

 

[RD.]

Good advice Al, but I have always disagreed with Jehmco's advice on how to run heaters through a controller.

"The principle of operation is to use conventional aquarium heaters and bypass their integral thermostats by setting them to their highest settings, then plugging these into a separate controller.230,120 and 24 Voltages available."

WRONG.

By setting heaters to their highest setting, if/when the controller fails ON, and they all can at some point in their life, you now have a situation where both heaters could be ON, and running at their highest setpoint until a person discovers the situation. I set my heaters just 2-3 degrees above the controllers setpoint, and then test, which ensures that the above scenario can never take place. In my set ups both the controller, and the heaters would have to fail at the same time for an overheating scenario to take place.

 

[Randys]

Another thing I learned the hard way was to place the sensor in a thermowell.

Weldless Thermowells from Brewers Hardware

Thermowells > Weldless Thermowells

www.brewershardware.com

I use Ranco controllers and had two sensors fail from getting wet before going to a thermowell. No problems since,

 

[RD.]

Another thing I learned the hard way was to place the sensor in a thermowell.

Or use a controller/sensor designed for wet applications.

 

[Randys]

Or use a controller/sensor designed for wet applications.

Ya, I did some checking around after the first failure and found lots of conflicting/vague info. Some listed as water “resistant” and some water “proof”.
The second failure was after shrink wrapping the sensor. It seems like I bought a kit online made to correct the issue I was having.
After that I was done with putting sensors in water.The cost of the thermowell was well worth it to me. It’s standard equipment for me now. The ID is made to match the OD of the sensor so it works very well.

 

[RD.]

The issue with controllers is that certain models are not manufactured with under water application in mind. Many are made to be used as area temp controllers, to cool/heat air in a room, not in an aquarium. That's operator error amigo. I've had sensors in water sans any form of thermowell for over a decade, and no issues, but mine were specifically made for underwater application. They typically cost more, so many people gravitate towards lower cost units, designed for non underwater application.

 

[Lepisosteus]

I personally wouldn’t worry about the tank getting to cold. Fish can handle a slow decrease in temp fairly well. Most handle medium to high 60s without issue. Slowers metabolism. I had angelfish in 40-60 degree water in university. We left the window open in the apartment after night of drinking. Tank was right beside the window hovering just over freezing. Same fish survived unbelievable concentrations of fermented barley, sugarcane, potatoes, and juniper berries.They weren’t happy but they lived.

 

[TexasMFK31]

I personally wouldn’t worry about the tank getting to cold. Fish can handle a slow decrease in temp fairly well. Most handle medium to high 60s without issue. Slowers metabolism. I had angelfish in 40-60 degree water in university. We left the window open in the apartment after night of drinking. Tank was right beside the window hovering just over freezing. Same fish survived unbelievable concentrations of fermented barley, sugarcane, potatoes, and juniper berries.They weren’t happy but they lived.

This is the reason I have 3 old school glass thermometers in the my system. The Inkbird controller I had failed (bad probe more than likely), and was reading the tank at like 87. I don't know why I found it odd, but eventually when I really noticed the fish slow down I checked. Tank was at roughly 65. After this I removed the Inkbird (won't buy their products again) and went with another brand and have had good luck. I would like to eventually build a micro-controller box for my aquarium so I can turn on air pumps as needed based on O2 levels, and see the temperature levels around the tank to point wave makers as needed. Gather as much data as possible and bring it to a screen for my info.

 

[Lepisosteus]

I’ve used inkbirds on and off but always monitor with something else as well. Last build I used an inkbird alongside the kamoer x4 dosing Pump which tracks temperature every hour over a 48 hour period. Currently I’m using the apex 2016 as my controller.