HOw ow does the temp have to drop to kll off a tank

mucky1957 · Jan 23, 2024

hi guys,

So we were away on holiday and my house boiler condensor pipe froze which over time backs up and then the boiler shuts down to prevent damage being done. The weather in the UK has been very cold...not Canada cold..but cold. I have an app on my phone which allows me to check house temperature and what the boiler settings are but it doesn't tell me if there is a problem.
A friend called in to the house to top up the tank, feed the fish and empty the skimmer for me last Wednesday and told me that the house was freezing. The hive unit that controls the boiler was showing that the hall was 5.6c. I knew straight away what had happened but had no idea how long the heating had been off. My friend only goes in once every 2 or 3 days. He showed me the thermometer in the tank and it was reading 16.2c. I usually keep it at 24c. There is a heater in the tank and it was working.
I contacted the boiler people who came out the following day and sorted the boiler out and got the heating working again. By then the tank was down to 15.6c.
We are now home and the tank and fish are 100% ok. I think I was very lucky.
So my Q is..how low does the temperature in a softy with fish tank have to drop before damage is done.

Doctorgori · Jan 23, 2024

I’ve had my furnace go out twice on me : the first time I had saltwater fish,tank got down into the 60’s (16c) …no losses

2nd time I had angels, discus, and killifish … 50’s for over 6 hrs, no losses

my take anything above 68F (20c) is ok ( not ideal but survivable) indefinitely for most any tropical reef fish

even tho I had no losses IME under 65F (18c) is playing with fire for any length of time (
pardon the fahrenheit)
btw oddly I don’t believe in heaters

taricha · Jan 23, 2024

I was thinking about this question myself. Got iced in away from my tank for 8 days. When I got to it, it was 22C, with all the fish out and happy to see food, and all the corals open etc. I only ever thought to check the temp, because the water felt surprisingly cold to the touch.

twentyleagues · Jan 23, 2024

I also have a boiler that has 5 zones. I heat my fish room and most of my tanks are unheated. I keep the room at about 73F ( sorry American here) the water temp in the winter is usually 68-70. My fish are fine. I do have heaters in my salt tanks but I keep them around 75-76f.

dennis romano · Jan 23, 2024

Just this weekend, the heater in one of the reefs died and I didn't catch it. I put my hand in the tank to move a frag and it was 64 degrees. New frags that I had just purchased two weeks ago crashed. The fish and established corals were ok.

ISpeakForTheSeas · Jan 23, 2024

I don't know how long it has to stay cold before you see the damage, but 23-24C (73.4-75.2F) is the lower limit for Ocellaris clownfish - the few studies I've found on it list 32C as the upper limit; below 23-24C and above 32C, the fish will eventually die from the temperature-induced changes in their bodies.

I can't find the article that discussed it (I apparently messed up the links in my post discussing it), but I believe 16-18C is where you can run the risk of seeing short-term damage from the temperature - again, though, I don't know how long that means; it could hours, it could be days, I'm not sure.

Physiological responses of the common clownfish, Amphiprion ocellaris (Cuvier), to factors related to packaging and long-distance transport by air

The physiological response of the common clownfish, A. ocellaris, to factors pertinent to air transportation conditions was studied in three stages: (…

www.sciencedirect.com

Thermal preference, tolerance, and thermal aerobic scope in clownfish Amphiprion ocellaris (Cuvier, 1830) predict its aquaculture potential across tropical regions - International Aquatic Research

The clownfish Amphiprion ocellaris is widely distributed in the coral reef ecosystems of tropical and subtropical regions of the West Indo Pacific, an area that hosts economically valuable species, and, thus, a suitable candidate for warm water aquaculture. This study determined the preferred...

link.springer.com

brandon429 · Jan 23, 2024

the degree of rebound you provide by lowering your light intensity makes probably the single most longevity impact of all

if you do not change/lower your light intensity, bleaching comes on faster. if you lower the light intensity during the event you greatly enhance ability for corals to not bleach out.

Reef Tank CPR - power outage biology, crash arrest, and recovery

https://www.reef2reef.com/threads/help-40-breeder-leaked-all-over-floor.857392/ Hawk82 thank you for posting clear documentation when the tank cracked you had to act fast, you separated the major components quickly and effectively Reef Tank CPR this thread will be to track emergency reef...

www.reef2reef.com

my own reef which was 15 years running at the time lost it's heater and I didn't know because I don't run temp checks. I noticed the corals bleaching one day and immediately lowered the lighting in response, fed well, and didn't catch it for about 2 straight months in the winter

when I felt the water inside the reef by happenstance it was so cold and when I did take the temp it was 68, for likely 6-8 weeks straight. amazed the system didn't crash totally. most of my corals bleached but then fully recovered because the light intensity control preserved some zoox.

knowing to change your light power in response to insults and challenges is a powerful reef control trick.