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Complete loss of all fish in my tank

1336 Views 18 Replies 14 Participants Last post by  starfire12
So I was doing a complete blackout to try and get rid a algae problem. Needless to say I did not think about the tank getting to hot, the lights were out so I did not worry about it. Noticed a foul smell in my computer room where the tank is, so I went looking for the smell found out it was my 46 gallon tank, uncoverd it to find every one of my fish dead. The temp had gotton over 90. So now I just got done tearing the tank completely down so I can start over with new supstrate and the works.
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how did it get to 90? did you not have the air conditioning on?
No I do not think the heater had anything to do with it. The room where the tank is can get kind of hot and our temps here were in the eighties or higher the last couple of day's. With the tank being completly covered it just got too hot.
I'm sorry for your losses.
Damn.. I've read about doing a blackout like that too, good to know about this as nothing was mentioned when i read it. Might want to consider going to the source that instructed you on the blackout and recommend they update to caution about this situation.

My condolences
There is no single source recommending a blackout. The blackout idea has been around for years, repeated by many people, over and over again. This is the first time I have ever heard of fish dying as a result. While I do not favor blackouts for any reason, including algae control, they are generally a safe (albeit ineffective) method to use. This was simply an unfortunate accident.

Last month was officially the hottest month on record — ever! As we continue to suffer such an unprecedented heatwave, it's probably best to spread the word that this sort of thing can happen. Anything that traps the heat inside a tank can raise the temperatures to an unsafe level with disastrous results.
Im a big proponent on keeping your tanks in the recommended temperature levels of the fish you are keeping. If that means not being able to keep certain fish, so be it. I live in FL, so heat is a very big issue. It has been so hot here I'm not sure the AC has shut off in over a week. I keep 3 African Clawed Frogs, which, as some of you may know, are cold water amphibians. I have a cooling fan directed at the water for evaporative cooling 24/7 to keep the temp in the low 70's.

If your ambient temperature is in the 80's, then your tank likely is as well. There are very few fish that can tolerate these conditions for long periods of time. In fact, the die off could have happened, black out or not. Fish can adapt to temperatures a few degrees higher than their optimal habitat temperature, but it will significantly reduce their lifespan.

In short, both heat and cool your tanks.
This tank is an open top, as the top I had broke a while back and I had not replaced it yet, any other time the temp of the tank is fine well within the safe zone. Unfortunaly it was my mistake for not checking the temp while it was covered. My stupid mistake cost me all my fish. I am not blaming anybody for what happened. Just thought I would let everyone know what happened so that it did not happen to anybody else.
There are lots of people looking at higher temperatures than they normally have. Over time we will all have to learn to deal with this. Look in the mirror if you want to blame someone!
Meanwhile, this case also can give us some guidance as to how we can effectively cool tanks for short term high temps. Covering the tank stopped a lot of the evaporation that cools. It also is likely to have trapped the heat from filters and powerheads under the cover. Those are two points to keep in mind when your tank is running too warm.

Many of us have to deal with high temperatures far beyond 80's so don't panic when it happens. Just use your head and do something!
Covering the tanks most definitely traps in the heat. All my tanks are covered in one way or another because I have cats. One has a glass top, some have actual lids, and all the others are open top with canopies over them. I attribute this to the reason why my tanks run hot even though I have the a/c set to 72° in the house. I even gave away all my heaters long ago because I realized I have no use for them.

This heatwave is horrible. It's not only affecting our aquariums, but imagine what it's doing to people's ponds. Plus, look at all the massive fish deaths in lakes and elsewhere due to the water temperature in native waters getting too hot. The drought isn't helping either.

Unfortunately, as the heat continues, I'm afraid we may see more reports of people losing their fish to heat.
Very important to share this info.
I am sorry you lost the fish. :-(

Aquariums lose heat not just through the top, but also through the sides. When an aquarium is covered, such as for a blackout, heat can get trapped. Usually this is not much of an issue, the room is so much cooler that the heat in the tank can still escape.

Heat escapes though evaporation. When a tank is covered (black out) there is no air movement post the water to carry away the evaporated water.
Heat escapes through the sides of the tank. Anything that stops air movement past the tank also reduces this method of heat loss. A thin material like a garbage bag might still pass a fair amount of heat, but a thick material like a dense towel is probably a very good insulator. (I have used towels to keep tanks warm in the winter).

Heat is added to a tank from the heater (which ought to not come on in situations like this), and from all the other equipment. The lights are off (obviously) but the filter and power heads are still running, and they are all water cooled pumps. The tank water flowing past the motors are carrying that heat into the tank. Even an air pump adds heat to the tank. The air that is handled by the pump is slightly warmer than room air, and this heat is added to the tank. The balance of increasing surface agitation which allows more heat to leave the tank usually makes this a reasonable trade off, but if there is not any air movement above the tank then this is not as good.
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Sorry to hear about your fish, but definitely a good lesson to hammer home for folks that no matter how confident you are, any significant change in your tanks should merit close watch in case of problems.

I'm in Arizona, so heat's a major issue. My main tank has a heater/chiller combo (expensive but worth it!) but if the power goes out I'm in trouble. Freezer always has a couple drink bottles of frozen water ready and I rotate fresh jugs of treated water in the frig so I can blend it in during water changes. If I have to do an emergency water change there isn't always time to bring water to room temp, and summer means tap temps significantly higher than room temperature!
I find the incoming water temperature is a problem for me as well. I had always relied on water changes to cool the tank but my water lines here are buried so shallow that the water can come in at near 85-90 degrees. I now use a reserve water barrel so that I have a stock of room temperature water ready for any time needed.
Rescape after total tear down.

So after a complete tear down of the tank I have rescaped the whole thing. What do you think. Any suggestions about placement of the stones and wood are more then welcome.
View attachment 52298
This is the first time I have heard of fatal results using this method as well. How long did you blackout your tank. Have you checked on your heater. There have been cases in which heaters have malfunctioned. What did you use to do the blackout.
The blackout was for two days, I had covered the tank with a flannel sheet. I did not have a problem with the heater before. Our temps here have been in the eightys and ninetys so the room where the tank is can get kind of hot. I am pretty sure that is why the temp in the tank went up so much.
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