I aim for 78 on all my tanks. That's what the controllers ' heaters and inkbirds are set to in any case.
In reality:
1.) My sps 40gallon tank 77-78
2.) My 32 gallon nem tank hovers around 77
3.) While my 50gallon frag tank runs 76-76.5
4.) The 210gallon tank runs around 75-76.5
I could and probably should turn the heaters higher yet I have always set them to 78 with their built in temperature setting functions
For the controllers and inkbirds I have the safe range set from (audible alarm and turn off and start heater):
1.) Sps tank 76.6-80 Alarm Never goes off, hydros also controllers this heater as final line of defense, inkbird is the 2nd line of redundancy, the heater has a controller plugged into the inkbird. Each line has slightly wider different ranges that are set with their own separate temperature probes should one fail there are 2 more safetys. So the heater on this tank always turns it'sself off. Only once has the inkbird alarm trigger when temp Probe came out of water and beyond force testing the hydros has never had to turn it off.
*This is actually my main tank hence 3 layers.
2.) Nem tank 76.5-79 Alarm Never Goes off. Just a finnex heaters with a inline temperature setter. With a inkbird only set up as a audible alarm.
* The is heaters not actually plugged into it.
So no real redundancy except for a audible alarm.
3.) Frag tank ugh, I expanded the range of the wifi inkbird to oh crap ranges 74-82 just so it doesn't keep going off and it still does at least once a week.
*Some Wifi inkbirds suck in my opinion triggers audible alarms even when temperature is fine, while others don't ever go off.
4.) 210 tank 75-80.
Only because I don't wanna turn the heaters controller higher than 78. I'm confident if I turned heater to 80 things would likely stay st 78. I will likely add a second heater plugged into the inkbird to help it get to temperature more efficiently so the heaters actual intermently turn of when at temp like my other tanks.
Forgive the in depth break down. Maybe it's helpful maybe it's not.
I do recommend redundancy on all tanks even if it's annoying audible alarm that keeps.beeping until you or someone goes check the tank out.
I couldn't imagine using a random heater and never knowing if it's cooking the tank or if the temperature is dropping because of a heater failure.
In the past I've have ran two heaters in tandem as a back up always a option if one fails. Currently I rely on the back ups to alert me if somethings wrong and I can address it then. 2 heaters would make you feel safer on vacation however.