How to Prepare a Tropical Aquarium for Winter Blackouts

Porky, the porcupine puffer fish smiles for the camera
Porky, the porcupine puffer fish smiles for the camera | Source

Learn how to make and use a tropical aquarium emergency preparedness kit for cold weather power outages.

When the power goes out in winter you can grab a blanket and put a sweater on the dog but your tropical fish or reef aquarium may be at risk of damage. A few simple precautions and a well-stocked emergency kit could save your freshwater or saltwater fish, live coral, aquatic plants or invertebrates from illness or death due to cold water temperatures or lack of aeration during a blackout.

So don't worry about your pet fish or prized corals dying during the next Snowzilla or Snowpocalypse; stock up on the appropriate supplies instead! Read on to learn what to do to protect your tropical aquarium or saltwater tank during cold-weather power outages.

Supplies You Will Need To Be Prepared

Essentials for keeping your fish tank warm during a winter power outage:

  • Mylar Emergency Blankets
  • Heat Packs
  • Battery Powered Aerator
  • Duct Tape
  • A printed copy of this page

Your kit should contain at least one Mylar emergency blanket, a battery powered aeration device or air pump, duct tape and as many 72 or 60 hour heat packs as you can reasonably store under the fish tank.

An Uninterrupted Power Supply or UPS can provide hours of power in a cold weather blackout, but it's best to have the rest of this kit on hand in case the power stays out longer.

How To Use Your Tropical Aquarium Blackout Emergency Kit

What to do to save your tank when the power goes out in winter

To protect your aquatic pets from cold-weather blackouts using these materials start by connecting and turning on the battery powered air pump as soon as the power goes out. For maximum oxygenation effect the battery powered air pump power pack should be outside the Mylar emergency blanket when you are finished.

Next, put four to six activated 60 or 72 hour heat packs evenly spaced around the aquarium. Attach the heat packs with a sticky side out loop of duct tape at the bottom edge of the outside of the tank.

Then wrap the Mylar emergency blanket around the fish tank shiny side in, leaving a bit of looseness around the heat packs. Tape the blanket together like a tent at the top. Use the duct tape to tape the blanket to the stand. Make sure that the power pack to the air pump is outside the Mylar emergency blanket.

#1 Mylar Blankets

You will need one or more Mylar emergency blankets. They can usually be found in sporting goods stores and in the sporting goods departments of most major department stores.

Decide how many you need to keep the heat in your tropical aquarium or reef aquarium during a blackout by measuring all the way around it. You should have at least eight inches more in combined length of Mylar emergency blankets than the circumference of your aquarium. When in doubt, get one more than you think you'll need. They are handy to have around and a double layer may provide more heat containment. A single 54" x 80" blanket will work fine for a 10 gallon tank. Two 54"x 80" Mylar emergency blankets will comfortably cover a 75 or 90 gallon aquarium.

Emergency Blankets - Mylar will help keep heat in your tropical aquarium during power outages

Emergency Mylar Blanket 54" x 80"
Emergency Mylar Blanket 54" x 80"

These sheets are also great for covering windows to keep heat in the room. If you use a Mylar blanket to cover windows in your tropical fish room put the shinier side facing in to your home to retain heat best.

I replace mine after using them because they don't ever fold up into the neat little packets again and the duct tape residue from this particular use makes it even more problematic. I just buy a few on Amazon as add-on purchases when someone in my household buys something else. I fold the old ones up as best I can and put them in my car's tool box to use in case we get stranded out in the snow.


Properly used, this kit should keep your tropical aquarium or reef tank warm and aerated for several days. More heat packs and more batteries will allow you to keep it warm and aerated even longer.

#2 Disposable Heat Packs

It's a good idea to have a good supply of emergency heat packs. 72 hour warmers are ideal but the 60 hour kind of Uniheat warmers seems to be more readily available. A good rule of thumb is to use two heat packs per 25 gallons of aquarium at a time. So, if you have a 75 gallon aquarium you may want to have 6 warming packs available for each 60 hours you may be out of power due to a cold weather power outage. If you use another type of warmer be sure to follow its specific instructions.

Please remember the heat packs must be used outside the tank, never put them in it!

Chemical Warmers - Keep water warm during power outages

UniHeat 72+ Hour Multi-Purpose Jumbo Shipping Warmer
UniHeat 72+ Hour Multi-Purpose Jumbo Shipping Warmer

I recommend buying the longest duration heat packs you can find. UniHeat is a good standard brand that I've had dependable results with for over a decade even when I've used them to ship live marine organisms through the mail in winter. They use a reaction of iron powder, activated charcoal, salt, vermiculite, sawdust, and water to produce their heat and they are biodegradable.


#3 Battery-Powered Aeration (Bubblers)

Tropical fish and reef tanks will benefit from steady aeration during stressful times such as cold weather power outages. While bubblers aren't used much in saltwater set-ups they provide water movement quite well in an emergency. A cheap, battery operated bait aerator will do in a pinch. However, you'll need to stock up on batteries before a blackout happens. While your usage may vary these devices usually work for about 8 to 16 hours on a set of batteries. I have a couple of battery powered air pumps for use during power outages, both of which will operate vigorously for about 12 hours per charged D battery. You can store a spare battery right inside the casing.

Just so you aren't surprised, please be aware that battery-powered aerators are usually pretty loud in operation.

Bait Aerators - Batteries can provide power to an aquarium bubbler during winter power outages

South Bend Bait Aerator (Blistered)
South Bend Bait Aerator (Blistered)

Bait aerators such as this one tend to cost a lot less than bubblers made for the aquarium industry and work just as well in a pinch. The mechanism inside is the same and I've actually found them to be a lot sturdier.

I keep three of a very similar model in the cabinet under my 95 gallon reef tank in case of emergency. They cost about $7 each when I bought them from the fishing department of my local Meijer store.


#4: Duct Tape - Duct tape sticks everything else together to keep your aquarium warm

A roll of two-inch wide duct tape is what it takes to bring this kit together.

While any duct tape will work I prefer duct tape at least two inches wide. A roll even wider than two inches would work great, too. It is just easier to tape all along the side of a Mylar blanket with wider tape and it gives you more sticky surface area to grab whatever you need it to.

General Cold Weather Tips for Tropical Fish

Move fish tanks away from windows to keep drafts to a minimum. If possible, keep your aquarium in the room you'd be most likely to close off and retreat to in the event of a cold-weather power outage. In case of a winter blackout, cover any windows in the room with blankets, sheets, or plastic and put a draft dodger or rolled up towel under the door. Hanging out in the room where you keep the tropical fish tank will also help slightly to keep it warm and make good use of your body heat.

An Uninterrupted Power Supply Can Protect Your Tropical Aquarium During Short Cold-Weather Power Outages

Or buy some time for you to take action if the power goes out while you're out

A UPS or uninterrupted power supply can protect your tropical aquarium from winter power outages for several hours. While most uninterrupted power supplies don't provide more than a few hours of power, they can protect your tank automatically and probably long enough for you to get home if the power goes out while you are out for less than eight hours. Then you can take other steps to keep your fish safe once you get home. The length of time your uninterrupted power supply will provide power during a blackout for depends entirely on what you have plugged into it. I suggest trying a dry run by unplugging the power supply and testing it to see how long it lasts so you'll have no surprises if it is needed later. I like the power supply shown below because four of its outlets automatically switch to the backup power supply if the electricity goes out. That way, one can pick and choose what to have backed up with an emergency power supply. For winter use, be sure to plug the heater into the automatic backup outlets on the strip.

However, while a backup power supply can provide hours of power, it's still a good idea to have the rest of the cold-weather emergency kit available in case the blackout lasts longer than a few hours. Also, if the power stays off long enough to cool down your home, simply providing power to your aquarium heater may not be enough to keep it warm so, at the very least, a Mylar emergency blanket should be wrapped around the tank to keep in heat.

Eight Outlet Battery Back-UPS - Four battery back-up outlets and four regular outlets

APC Battery Backup & Surge Protector (BE550G) - 550VA 8-outlet Uninterruptible Power Supply (UPS)
APC Battery Backup & Surge Protector (BE550G) - 550VA 8-outlet Uninterruptible Power Supply (UPS)

This uninterrupted power supply gives you the ability to pick and choose what you want to stay on in an emergency. I like this model of battery back-up because it provides eight outlets so you don't need an additional power strip to run aquarium equipment that doesn't need to stay on in a power outage. You can plug it right into your GFI breaker and it should have enough outlets for all your aquarium equipment. I would like to eventually get this model to replace my 4 outlet UPS and power strip.


Reduce the amount you feed your fish until the electricity comes back on to minimize the build up of wastes and degradation of water quality in your aquarium.

© 2011 Kylyssa Shay

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Is Your Tropical Aquarium Ready for Cold Weather Power Outages? 84 comments

RinchenChodron 2 years ago

Great advice and pretty easy!

rajatwilightdream 2 years ago

Excellent tips! I do have a Tropical Aquarium in a small way. For uninterrupted power supply, I have connected my Inverter to the Aquarium power point. My fishes are always enjoying. Keep writing!

anonymous 3 years ago

When we kept tropical fish I always worried what would happen if we lost power for days. This is an excellent resource.

anonymous 3 years ago

Thanks for the great information.

moneyrat profile image

moneyrat 3 years ago

I have a computer UPS connected to my Discus Fish aquarium. It can keep hold power for several hours. This is specially for nighttime.

anonymous 3 years ago

I never thought about what to do in the event of a power outage! I take care of a 300 gal tank at my church! Thanks for this info!

makorip lm profile image

makorip lm 3 years ago

It cost my homeowners insurance over $4000 when our 8 day power outage here in Seattle blew out my 6 year old reef aquarium. Outages are real and costly. Good lens!

weakbond profile image

weakbond 3 years ago from Johannesburg

Highly informative lens ,thanks for sharing

fbcivcoming profile image

fbcivcoming 3 years ago

I don't have a tank but this makes me think of Hawaii and how it must be like your own little piece of the tropics.

anonymous 3 years ago

Thank you for these wonderful tips :) Congrats for your LOTD!

agagata lm profile image

agagata lm 3 years ago

I wish I had read it two weeks ago when the electricity went and I lost 5 fish because of it... I'll bear it in mind for the future though. Thanks!

TCG master profile image

TCG master 3 years ago

OMG I love my fish this lens is SO helpful!!

street2linen profile image

street2linen 3 years ago

Great lense and information about preparing ones aquarium.

choosehappy profile image

choosehappy 3 years ago from US

Wow. I'd never even thought about that issue before but it certainly is one. (I guess that kinda reveals I don't have an aquarium or fish ;)--- Awesome tips--very helpful! Congrats on lotd too.

graphite75 profile image

graphite75 3 years ago

Great tips. I love tropical fish. Congrats on LotD!

anntag 3 years ago

That's really good to know how to take care of your aquaruim fish in an emergency.

jntnevins lm profile image

jntnevins lm 3 years ago

Very nice lens. I don't have an aquarium now but I used to. When I had one I didn't think about having a kit. This is a great idea.

mrknowitall54321 profile image

mrknowitall54321 3 years ago

Well done on achieving the lens of the day, very good lens with lots of fantastic information.

Elyn MacInnis profile image

Elyn MacInnis 3 years ago from Shanghai, China

What wonderful ideas. I love your photo of the sweet fish in the introduction. You wouldn't want to lose such a sweetheart just because the electricity went out! SquidAngel sand falling gently on you and your tank!

Camp April profile image

Camp April 3 years ago

Congratulations on LOTD. Way to go. Lots of great tips I hadn't even thought of. Thanks

TaraWojt profile image

TaraWojt 3 years ago

Lots of great tips to keep your aquarium safe. Congratulations on LOTD, blessed!

Judith Nazarewicz profile image

Judith Nazarewicz 3 years ago from Victoria, British Columbia, Canada

Congrats on LOTD! Really great tips for preparing your aquarium.

Hannah Writes 3 years ago

Congrats on being LotD! Blessed.

livingfrontiers 3 years ago

This is such a great idea, and it makes me happy to know I am not the only one who worries about this exact problem! I am very grateful for your knowledge!

Wish List Gifts profile image

Wish List Gifts 3 years ago

Thanks for this - I actually lost a small tank to a power outage right after I started the hobby. Lots of hard work and lovely animals lost.

cleanyoucar 3 years ago

Great tips! Thanks for sharing them.

pigwear profile image

pigwear 3 years ago

Great lens...I haven't thought about the need for this but in a northern climate it would be very usefule.

TopChristmasToysGifts 3 years ago

Congratulations on Lens of the Day.... Thanks for the tips in case of power outage.

Sara Krentz profile image

Sara Krentz 3 years ago from USA

I've been wanting an aquarium, but it wouldn't have occurred to me to have an emergency kit for a power outage. Thanks for the info.

heehaw lm profile image

heehaw lm 3 years ago

although i do not have any salt water fishes, but this is a good knowledge for me. thanks for sharing.

nicenet profile image

nicenet 3 years ago

I don't have a tropical acquarium.Congrats.

TommysTips profile image

TommysTips 3 years ago

Congrats on LOTD - great information on keeping your fish safe and warm!

TheLittleCardShop profile image

TheLittleCardShop 3 years ago

I don't have a tropical fish aquarium now, we used to have one some years ago and I know what is not to be prepared for power outages. We would like to have one again and thanks to your tips we will be prepared this time. Congrats for your LOTD! :)

tommydillard 3 years ago

thank you very much about these ideas i never even thought of it cause i live in sunny California

nhotdeals profile image

nhotdeals 3 years ago

Great ideas, granted I do not have fish right now but I never thought about it

Resident-Nerd profile image

Resident-Nerd 3 years ago

Very nice information. Many people forget about there pets in these conditions. Thank you. Congrats on LofD.

JadaFuego 3 years ago

Great LOTD!! I am sure my fish would thank you!!

wyzeguru profile image

wyzeguru 3 years ago

I'd never even given this a thought! Our power supply hardly ever goes off but that's no excuse not to be prepared is it?

anonymous 3 years ago

Good stuff, sound information. Congratulations on getting LotD!

CamelliaPenny profile image

CamelliaPenny 3 years ago from South Carolina

Really useful info. Congrats on LOTD!!!

rdcbizz profile image

rdcbizz 3 years ago

I love aquariums.

MartieG profile image

MartieG 3 years ago from Jersey Shore

Good information! Congratulations on a well deserved LotD! :>)

zafsot profile image

zafsot 3 years ago

This is a great lens, i am new here and i find squidoo just amazing

anonymous 3 years ago

I was here a while back and remember being so impressed that I had not seen this information anywhere else and would imagine many have faced this situation with widespread power outages. Congratulations on LotD honors!

writerkath profile image

writerkath 3 years ago

Whenever the power goes out at home (NH), I'm usually grateful I have the woods (backup "outhouse"), gas stove, and woodstove for heat... But I have sometimes thought about certain things like this... "What if someone needs some medical necessity that uses electricity..." but I have to say I hadn't thought about aquariums, simply because I do not have one. But this is very important for people to do have one. I hope that people who have aquariums find your lens and prepare. Nice, thoughtful (and thought provoking) page here, Kylyssa! Squid Blessed! :) Kath

cyberflutist profile image

cyberflutist 3 years ago

I've never had a tropical aquarium, but they are beautiful and it would be a shame if one were damaged in a power outage.

Fox Music profile image

Fox Music 3 years ago

Thank you for sharing this lens "How to Prepare a Tropical Aquarium for Winter Blackouts" and congrats on Lens of the Day !!

ShariBerry profile image

ShariBerry 3 years ago from Michigan

Since I have never had an aquarium I've never given any thought to people who do and what would happen in a blackout. What a great lens with so much good info for saving your fish. Thanks for sharing.

vectorland 3 years ago

Great lens and congrats on getting LOTD also :)

Bonfire Designs profile image

Bonfire Designs 3 years ago

Congratulations on LOTD - great emergency information!

LeeD LM profile image

LeeD LM 3 years ago

Great information - I actually just setup a reef aquarium (its still cycling so no living creatures yet) and we just had a huge storm. I was afraid of losing power and I did get a battery powered aerator but never thought about a mylar blanket. Thanks!

PastorKay profile image

PastorKay 3 years ago

Car jumpstarters usually have a spot to use as a regular outlet. You could use one of these and then recharge with your car (if you've got one).

JoshK47 3 years ago

This is an incredibly useful lens - never even thought about this before! Congrats on LotD and here are some SquidAngel blessings for you!

poldepc lm profile image

poldepc lm 3 years ago

Congrats on LOTD

Faye Rutledge profile image

Faye Rutledge 3 years ago from Concord VA

Great information to have. Congratulations on LotD!

LadyDuck 3 years ago

Great lens of the day. Very good tips to protect our little friends the tropical fishes

soaringsis 3 years ago

Thanks for sharing info. Congratulations on your LotD.

restaurantsinlebanon 3 years ago

great lens with nice ideas

anonymous 3 years ago

That is Great. Great tips and ideas.

Elaine Chen profile image

Elaine Chen 3 years ago

congratulation for the LotD and Purple Star reward; I just send this Lens URL to my best friend who love tropical aquarium.

aka-rms profile image

aka-rms 3 years ago from USA

Congratulations, this lens was selected as LotD today. You can read all about it here:

NewUsedCarsSacramento 3 years ago

Congrats on being LOTD. Id love a tropical aquarium.

Carpenter76 profile image

Carpenter76 3 years ago

Nice lens. I like an aquarium, but I think it's so much work!

Tarra99 3 years ago

Congrats on LOTD Kylyssa

anonymous 3 years ago

Congraulations on LOTD

JeffSawyer 3 years ago

Congrats on being LOTD

lav777 lm profile image

lav777 lm 3 years ago

great information:)

racingdatabase 3 years ago

Great tips - we live in Scotland and regularly have outages here! :)

WriterJanis2 profile image

WriterJanis2 3 years ago

Good information to know.

Gypzeerose profile image

Gypzeerose 3 years ago

Very helpful, well put together and useful. Blessed.

anonymous 3 years ago

Aquarium care is so important and is often overlooked. Great lense!

Craftypicks profile image

Craftypicks 3 years ago from Las Vegas

My brother had this exact problem with his tank during Hurricane Sandy. He was out of power for 2 weeks and worked hard keeping his fish alive. This included boiling hot water on a BBQ for them. He lost a few but most survived. I told him to set his tank up at the home of a friend who had power, but he kept hoping the power would come on.

favored profile image

favored 3 years ago from USA

Congratulations on LotD. Proper care for an aquarium is something people may not think about during a power outage. Nicely done.

Jogalog profile image

Jogalog 3 years ago

Congratulations on LOTD! I don't havea an aquarium but I'm sure I'd find all this information very useful if I did.

CampingmanNW profile image

CampingmanNW 3 years ago

Congratulations, I see why you won a purple star and LOTD. Excellent Ideas all. I have used similar tricks to keep my Koi ponds aerated and warm enough in the Pacific Northwest Winters. Nice job on this lens

SteveKaye 3 years ago

Congratulations on receiving the LOTD. This is very good.

corydoras profile image

corydoras 3 years ago

My tropical aquariums over the years have weathered multiple power outages without problems or anything more than a blanket wrapped round them and some styrofoam insulation, but I don't believe they've ever dealt with anything longer than 12 hours. Water has a high heat capacity, which means it cools much slower than air and a short power outage doesn't do too much harm to the average freshwater tank - unless it has been overstocked. Then aeration becomes a big deal and backup aeration is essential. I couldn't find a battery-operated pump when I had fish, which is why I didn't use one. I haven't kept marine, but wouldn't be surprised if they were more sensitive. You've many good ideas here. I think I'll try to find a mylar blanket for my lizard tank. I already have heat packs for her.

BillyPilgrim LM profile image

BillyPilgrim LM 3 years ago

Good tips! I'm just starting to keep fish so this is very useful. Thanks x

sherioz 4 years ago

I used to keep fish in a huge tank. We didn't have problems with cold, but if the electricity goes off then the filters shut down. This is an excellent article for anyone relying on electricity for their tank.

anonymous 5 years ago

I don't have a tropical fish aquarium but I can sure understand the need to be prepared with an emergency kit for those winter power outages, we sure do get them in Fargo and the apartment cools down very quickly in cold weather. I have not seen information on this anywhere else, well done Kylyssa.....and the tropical fish of the world thank you!

huvalbd 5 years ago

Clever solution--I like reading your lenses, which often teach me clever solutions.If you have a way to boil water, perhaps in a pan in the fireplace, rechargeable heat packs could be used too. To recharge, boil until the insides are entirely liquid again. To activate, through the covering, "click" the metal disk inside which starts the chemical reaction to release the heat. They should go through as many as 500 recharges before being worn out and needing to be discarded.

anonymous 5 years ago

This is a beautiful lens on how to take care the temprature of aquariums for warm tropical fish.

Jack2205 profile image

Jack2205 5 years ago

This is a great topic. Blessed by a Squid Angel.

anonymous 5 years ago soon as I read your tips...nice lens

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