Triple the Heater Safety

[Reef AquaCult]

Protect your tank against what I would consider the worst thing other than tank seam failure in the hobby and that's frying your tank.

I use an Apex mostly for monitoring and NOT controlling, but its one thing I use to control the temperature in my tank. I set the Apex to turn on at 78F and turn off at 79F. I have 2 Eheim Jager heaters both set to about 81F. Consider getting 2 lower powered heaters rather than one large heater - if one fails on then you have twice the amount of time to catch and remedy the problem. In addition, the heaters are plugged into an Inkbird temperature controller with separate temp probe. Its an inexpensive solution to make your setup even safer.

I also have an ink bird temperature controller ($30 USD) that plugs into the apex outlet and works as a backup.

How it works.

Safety 1 - Set Apex to 78 - 79 - make sure probe is calibrated and secured to a low spot in tank, sump with good water flow. Mine is next to return water flow.
Safety 2- Set Inkbird to 80 +- 0.5F - plug into Apex - also make sure probe is secured into a high flow, low lying area of the tank/sump
Safety 3 - Set Heaters to 82F - Plug heaters into Inkbird - when the heaters receive power they should pretty much always be heating. Make sure heaters are secured to low lying, high flow area but not right next to temp probes.

Failure scenarios
Heaters Fail Off - Apex will trigger alarm notifying you of a cold tank - no big deal - coldest my home gets is Low 70s. Not good but no deaths. Also unlikely because I have 2 heaters.
Heaters Fail On - This is a disaster you want to avoid! This takes some thinking.

Alerts on Apex
1. Alert if temp > 81
2. Alert if heaters on for more than 3 hours
3. Alert if amps drawn on heater outlet exceed your regular maximum by 25%

Equipment safeguards to failure
1. Apex - your first line of defense - turns off when temp > 79
2. Inkbird - plugs into Apex outlet - if Apex fails, temp will rise to 80-80.5 and Inkbird will cut power.
3. Heaters - If both Apex and Inkbird fail - VERY unlikely - then heaters will cut off at 82F

If all fail off - then your tank will get colder - if your home is very cold then you might need some type of audible alert. My home is always around 74-75F which won't kill any fish or corals and when I feed fish I will notice the tank is cooler. Another way is to have a cheap digital reading easily visible from tank.

If all fail on - VERY UNLIKELY but you can (and I do) use 2 lower watt heaters because both heaters won't fail on at the same time - this gives you more time to save the tank.

BOTTOM LINE
Plug a separate temp controller into your standard controller with separate temp probe in case one of them fails. Get 2 lower wattage heaters rather than one high powered heater.

Please let me know your thoughts or if you have any improvements.

 

[ca1ore]

I'm not personally a fan of the inkbird controller. Had two fail on me, though I understand they have redesigned the probe to be more SW resistant. I much prefer the Ranco, though it is more expensive. I actually have been using three heaters. Calculate the wattage required for your tank, divide that number by two, and buy three of that value. Although I do have titanium heaters without an internal thermostat, I think those like the EBJ offer an additional layer of protection. I'd also suggest that you've not addressed the apex-as-single-point-of-failure. Better, I think to run truly redundant/independent controllers.

 

[Tastee]

I run a version of this with 2 heaters and a chiller as where I am we don’t centrally heat or cool our house 24x7, so I need to cover both bases.

Main heater controlled by Apex, internal thermostat set to turn on just < Apex on. Apex keeping temperature in a 0.5C range so internal thermostat would turn off about 1C > Apex off.
Backup heater not powered or controlled by Apex, but by direct power conx and internal thermostat. Set to turn on just < Main heater on.
Chiller powered by Apex but controlled by internal thermostat, Apex will override however.

Main heater fails on - Apex shuts it off. I would then have to detect this situation manually by testing the main heater. I hadn’t thought of that before so that is something else I will add to my regular checking, thank you!
Main heater fails off - Backup heater kicks in, Apex sends alert.
Apex fails Main heater on - Main Heater internal thermostat shuts it off, Apex sends alert (hopefully, depends on Apex fault).
Apex fails Main heater off - backup heater kicks in, Apex sends alert (hopefully, depends on Apex fault).
Backup fails off - won’t cause an issue normally but do need to periodically test the backup to ensure it is still working.
Backup fails on - biggest risk in my setup, Chiller will turn on and fight the backup, if it doesn’t win Apex will send an alert.
Chiller fails off - Apex sends alert.
Chiller fails on - Apex turns it off and sends alert.

Obviously there are ways I could improve this (e.g. the Inkbird for the backup as per your setup), but hopefully it sparks some thoughts for other’s setups. Happy reefing!