When do you need a chiller?

[LesPoissons]

Hey guys,
Its gotten cooler here and the heat is now on. My tank is usually 80 but has now gone up to 82. Ive had issues with my plating montis bleaching over the last few weeks and last week my duncans have closed up. I though the bleaching was due to nudibranch since the other corals were fine including the encrusting montis but now the duncans seem irritated so Im wondering if its the temp increase? How warm is too warm? Everything else seems happy.

 

[Montiman]

I am in Phoenix were it was 101 yesterday in November and I have had my tank regularly get to 82-83 degrees in the past without an issue. There are however a few things to keep in mind.

Corals and fish are not found in the same temperature across the world. While shallow water corals may regular see temperatures of 84+ deep water corals may normally be in 72 degree water. I have seen deep water fish react very badly to 80 degree water.

There is more risk associated with high temperatures than lower temperatures. When you maintain temperatures of 82-83 degrees it only takes a minor stress event to trigger bleaching while corals can be more forgiving at a lower temperatures.

Lastly if your tank regularly gets into the low 80s the chances of an unforeseen event leading to the tank getting into the mid to high 80s is more likely. This could be a heat wave or broken AC.

So for me I do run a Chiller for a few reasons.
1. A wider variety of animals seem happy at 77-78 even though plenty do fine in warmer water.
2. I have had fewer bleaching events and have a bit more margin for error with maintaining other parameters.
3. This is the real reason. I once had the AC go out and lost everything in the tank. AC guys came right away but it took 3 days to completely replace the old system. It was 120 degrees outside and over 130 inside. no matter how many icy water bottles and fans I had the tank still got to 90+ degrees. Having the chiller gives me huge peace of mind.

You can decide if a chiller is for you. Before a chiller I would try some cooling fans. Fans can lower the temperature 2-4 degrees in many cases but they won't get you the 10-30 degree drop you might need in an emergency.