Minimum Critical Temperature for Power Outage Plan

[braappn]

What are your thoughts on the minimum critical temperature a tank can be allowed to drop to during a power outage / cold house situation?

I am considering setting up a battery backup using an auto-switching inverter and a large battery. This would obviously power circulation but also a backup low wattage heater.

In my situation a worst case scenario ambient temperature in the neighborhood of 45 degrees must be considered. In figuring the size of the heater and amp hours of battery power required, the lower it drops the better.

So at what temp would you set that emergency heater?

 

[nautical_nathaniel]

I would say you could get it down to around 68-72 without too many problems short term. Depends on the corals you have too since some LPS/softies are deeper water species that can tolerate lower temps. The biggest thing to prevent is the rapid decline in temperature. If the power goes out and it's cold outside and your home is going to get cold too, I would be covering up the tank and wrapping it in blankets or thermal reflective sheets (that shiny foil stuff included in emergency kits). Make sure you have an air pump for oxygenating the tank too. You want to keep the temperature stable for as long as possible and if it is going to drop, it needs to drop slowly. When the power comes back you also need to make sure that the temperature rises back to 78 or so slowly as well.

 

[braappn]

Thanks for your thoughts. I had not thought about bringing the temp back up slowly. This will end up dictating how low i let it fall. I will have no way to control the speed at which it comes back up in this situation of being away from the tank.

It will never get super cold if I am home because I can crank the wood stove. This planning is mostly for being away. The system is already insulated on all non-viewing sides by styrofoam insulation.

I do not intend to keep any super delicate species, in part because of what we are discussing here.

 

[PAXpress]

Also with lower temperatures more dissolved oxygen so potentially less issues with needing lots of circulation or fish oxygen deaths. With a larger tank size you'll have to worry less about a fast drop in temp as well.

 

[Lionsreef]

We experienced a 3 hour power outage this past Saturday due to high winds knocking down power lines in the area. During this time my water temp dropped from 78 to 72.8 before the power came back on. Unfortunately, I've lost 2 SPS frags so far that RTN'd within 24 hours. I have to assume it was due to the cold shock as all other parameters were stable.

 

[Lionsreef]

I have now lost 5 corals in past 5 days due to power outage. The SPS frags have suffered first but now my acans and wilsoni corals are showing stress and not puffing up.