Yes. It’s 200 gallons total, so a I have a pair of 300-watt Schegos controlled by the Inkbird (and monitored by the Apex overlord) and a separate 500-watt Hygger controlled and monitored by the Apex.
If either of the 300-watt heaters fail and the 2-hour runtime on the Inkbird is exceeded by the failover heater, the Inkbird kills the heaters and I get a warning. If the single heater can't keep up with the temperature, the Apex engages the backup heater as needed - and I get a warning.
If the Inkbird fails and/or the heaters get stuck on - the Apex kills it and I get a warning. And if the Inkbird fails and/or both heaters fail or shut off - the Apex turns on the backup heater and regulates temperature - and I get a warning.
If all three heaters fail (extremely unlikely) - I also get a warning.