At what low tank temp will fish die

[Ping]

I just got a call from a friend who has been without power for about 24 hours now. He is working hard to keep his tanks going. He has an inverter and methods to maintain 02 but his temp is down to 69.

At what temp will his fish die?

[blueboy]

get some heat packs, and put them in the sump. or hot water bottles in the sump.

[BIGBIRD123]

Heat packs in the sump near the most flow will help. If he has an inverter, seems like I'd hook-up a heater for a while.

Steve

[caferacermike]

I'd say you are safe down to about 70 or so, it's the sudden drop in temp I'd be more worried about. Same thing for bringing it back up. Do so at a decent pace.

[Ping]

It is a 240 and his heater draws too much power for the inverter. His small heater is not putting a dent in it. Hot water bottles may help.

A slow raise in tank temp makes a lot of sense. thanks all.

[blueboy]

i've been putting hot water bottles in my sump the last couple of nights. our heater is having a hard time keeping up in our old house.

[Bill S]

Wrap the tank, if he can. Blankets, etc. Cut the sump and/or fuge out of the cycle. Minimize loss from evaporation. Hard to do while keeping circulation up. If he has a gas grill or cooker, heat up water. Put water into ziplocks and drop them into a hot pan of water heated on the grill/cooker, and cycle them.

[brewercm]

I had a problem once with my chiller getting stuck on over night (1/2 HP) on a 100 gallon tank. My tank ended up around 54 to 56 degrees and everything made it except a maroon clown.

[brewercm]

BTW, I did bring the temp back up to it's normal over about an sixteen hour period.

[ratboy]

About 10 years ago my reef weathered a 5 day icestorm with no power by adding bags of water heated on the stove to the tank (replaced every 2-3 hours) and a battery powered pump for air. I think my tank got down to around 60 (fish were starting to look verry unhappy) before I came up with this heating method. The only thing I lost were a few heads of torch coral that got cooked by a bag of water that was too close, for too long.
Right now my 400 gal. reef worth of critters are ridding out this cold weather in my garage in a giant tub. I have the whole thing wrapped in plastic and only open it to feed the fish. 3 decent sized heaters and 800W of MH keep it nice and warm. My temp has definatly fluctuated over the last few days but everything is still doing fine.
Tell your buddy good Luck!

[brewercm]

One other thing. When I was big into fishing we used to go get bait minnows and ruby reds. We'd take the bags they put them in and place them in the refrigerator, sometimes for a few days because we knew the bait shop wouldn't be open when we got there. What this does is slows down the fish's metabolism and they use less air and requirements for food etc. Same as those of us that have ponds that freeze over or just get cold during the winter yet your fish do just fine.

Not saying that reef fish are the same since they come from a different region, but they still withstand cold temps in the wild at times also. Your best bet is to bring the water back up to a normal temp but just don't do it too quick.

[AquaDen]

Living in Florida most of my life I spent a lot of time on the reefs and in the water. When the tide changes (2 or 4 times per day) the temp changes drastically and over a very short period of time. While the water is in the shallows it heats up very quickly. When the tide goes out the hot water gets pushed past the reefs and there is a rapid change in temp.