Is Duct Tape Safe for Fish (1)

Is Duct Tape Safe for Fish: Let’s Find Out!

If you are an aquarium enthusiast, it often happens that there are leakages and broken parts. And all we know how troublesome is to fix a broken part.

In this case, the first solution that may have come to your mind is using duct tape.

But is duct tape safe for fish?

No, duct tapes may kill fish when used for a long time. But when used for a short time of about 30 minutes, it is okay to use them. Duct tapes are mostly used in repairing and paper use. They are water-resistant but not quite waterproof. They can resist water for a maximum of an hour. When used in aquariums, their chemicals may mix into water and become risky for the fish. 

You might be still wondering about the chemical toxins that might affect your fish. Do not worry. We have discussed all the effects of duct tapes along with the best alternatives.

So, to know more about the different tapes used in aquariums, let’s see what is there in the next section. 

5 Ways Duct Tape Could Affect Your Fish

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As you might be wondering, all types of duct tapes are obviously not harmful to your fish. But we are not just talking about the chemicals. Duct tapes in your aquarium can harm your fishes in a lot of other ways by obstructing their regular lives. 

But what are the effects of duct tape on your fish? We have discussed them below. Let’s jump in.

Way 1: Having Fish Stuck on Loose Tape

Duct tapes are water-resistant but they are surely not waterproof. Duct tapes remain in place inside water for about 30 minutes. After that, it will loosen its grip and come off from the fixed part. 

When the duct tape becomes loose, it may get stuck to the fish in your tank. So, if the fishes roam freely inside your aquarium, they may move past the loose tape.

In such cases, they may get stuck in those tapes due to the sticky material or any loose knots. This situation can be quite alarming for your fish. 

The fishes may try to get out of the loose tapes and end up harming their external skin. From these wounds, they may develop an ulcer or bacterial infection. This might ultimately even cause death!

However, if unfortunately, such cases arise you can get API Aquarium Salt to recover these kinds of fish diseases. It also enhances respiration for fish in freshwater aquariums.

Because even these loose tapes can stick up in the gills of the fishes and other aquatic plants. This causes them difficulty in breathing. As a result, it becomes impossible for them to get out of the sticky tapes.

Way 2: Getting Exposed to Chemicals

Starting with the components of duct tape, they are made of several layers. There are different chemicals used in duct tape.

You’ll be surprised to know they have a polythene coating, a cotton mesh, and adhesive on one or both sides. The essential component that makes duct tape sticky is the adhesive.

Rubber components are included in its formulation. This results in a stronger and longer-lasting connection.

Also, duct tape has a thicker adhesive covering applied to the substrate than regular ones. This adhesive can be very harmful to your aquarium buddies.

The adhesive in duct tape is often made up of butyl rubber compounds, which are not very soluble in water. This is taken by fishes and will be in the digestive system causing harm to them. So, it is safe not to use them at least in the inner layer of your aquarium.

However, it’s not like we never face the digestion problem of our fish. whether its for the duct tape or other infectious issue our fish’s digestive system can be risked.

At this point if you want my suggestion then I’ll recommend some probiotics. See, probiotics used in the diets enhances protein and amino acid digestion in fishes. Therefore, you can use the following probiotics as your fish meal.

Way 3: Jamming the Air Stone

An air stone, often known as an aquarium bubbler, is a porous stone used to diffuse air into a tank. It enhances the tank environment.

The air stone releases little bubbles into the water which has oxygen. It is better rather than the larger bubbles produced by air filtration systems. They often can float on water and there are ways to keep the stone down.

A loose duct tape can jam your air stone. If the duct tape wraps around the stone, it will be unable to produce small bubbles. This will hinder the production of oxygen inside the water. It will also cause the aquarium water to be stagnant.

Way 4: Disrupting the Lifestyle

Most important of all, duct tape can cause a serious interruption in the lifestyle of your fish. Most fishes can communicate with each other. They do this by using gestures and motions. It is seen to be done by the highly regimented synchronized swimming of schools of fish.

Also, some species employ electrical pulses as signals. Others use bioluminescence. Some fish also emit compounds. Then the others can detect them through the senses of smell and taste.

There can be loose duct tapes floating in different places inside the aquarium. For this, it becomes difficult for fish to communicate and to move around.

Morever, their technique is also blocked as they lose signal. Most fishes move in a formation that can be disturbed due to the blockage of duct tapes. 

Clownfish can’t swim very well. They spend much of their time hiding among anemones and when they do venture out. Their swimming patterns are unpredictable.

For this, any loose floating object or duct tape causes disturbance in fish’s movement.

Way 5: Interrupting Light Exposure

Aquarium lighting is aesthetically pleasing. It brightens your tank and makes the colors of your fish appear more vibrant. Lighting ensures your fishes’ overall well-being by providing energy and oxygen. It also ensures growth for photosynthetic plants and critters. 

Long story short, all life in your aquarium environment requires light to thrive. This includes fish, plants, corals, and microorganisms. There are different factors that are to be considered for selecting your aquarium light.

Have you used duct tape for your aquarium light fixture or to stick your light in place? It will not solve the purpose. Rather, with time the tape will come off and blur the lighting. 

As we know, duct tape has a layer of cotton mesh or polythene layer. This layer is blurry for which light cannot pass through. For this reason, it might get in the way of light exposure and make a dark environment inside the aquarium.

So, instead of attaching the lights using duct tape why don’t you use LED tank mount bracket. Do you wanna know what kind of brackets we’re talking about? We already heard you and came up with the following list. Take a look and get your brackets to hang the lights accurately.

What Kind of Duct Tape are You Using: Is it Safe for Your Fish


Choosing an aquarium-safe tape is quite a task. There are different kinds of chemical adhesives in them.

So, what type of tape should you use?

Before buying a tape for aquarium purposes, look into the precautions. You need to read the tape description. If it is mentioned to keep the product away from children and animals, it is not safe for fish.

Also, the water-resistance level of the tape should be checked for aquarium use. There are only a few counted tapes safe for aquariums. But you must keep in mind that all of them are not safe for fishes or any other aquatic life.

Some special tapes and glues should be used in an aquarium. For instance, Nashua 3 Tape is specially manufactured for underwater use. There are many of this sort. Let’s see them in more detail below.

Silicon Sealant

Silicon glue is considered safe for your aquarium.

Now, most of these sealants is made up of 100% non-toxic silicone for use on freshwater or saltwater aquariums. It can hold on to the water for a long time. It is durable and flexible. They conform to even small pipe sizes, tight corners, and frigid temperatures. 

As a result, it’s ideal for use in aquariums as it can withstand melting, weathering, and tearing. If you go for silicon sealants, here are some of our top picks.

They are readily available at all stores that sell aquarium items.

Gorilla Tape

Gorilla Tape is made up of three layers. It has-

  • a weather-resistant outer shell, 
  • a reinforced fabric backing
  • an adhesive layer (this layer is twice as thick as duct tape)

For this reason, this allows the tape to better envelop and hold uneven surfaces even underwater. 

But Gorilla tape is harmful to humans and animals if ingested or breathed in any amount. So it’s most definitely also harmful to aquatic creatures. In their packaging, they are said to be kept away from children and animals. They also have medical emergency instructions. 

This makes the tape harmful for aquatic use though it has a good performance in being waterproof. 

Electrical Tape

Electrical tapes are not harmful for use inside an aquarium. But they are not quite effective for using underwater. They will get loose soon after getting exposed to water and lose bondage.

Technically, waterproof electrical tapes are not made as they are impractical. This is because of the adhesive used in this tape. It loses its properties when it comes in contact with water. It will not hold in place and the shape will deform. 

However, they are not meant to be waterproof either. This is as electrical substances are strictly said to be kept out of water. Rather, these types of tapes are made water-resistant and weatherproof to a level. 

Now, you’ll see that it is instructed in electrical tapes to keep them away from water and substances. But we don’t see it as a problem for us. You see, water is a conductor of electricity and therefore extremely hazardous. This makes sure that the tape works under a little amount of moisture..

Although electrical tapes are not harmful to aquatic life, they won’t last long in a large amount of water.

Scotch Tape

Scotch tape is the most common type of tape that is used in almost every fixing job. They are deemed non-toxic. Some individuals claim that it hasn’t harmed their aquarium fish. So it can be used for aquarium purposes but its efficiency is doubtful. 

The thing is- scotch tape is prone to becoming moist and falling off easily. It is also not very strong in holding its place as it is mostly used on paper. 

As a result, it is not recommended to use scotch tape to patch damage within the tank. It should suffice for fixing aquarium equipment. So, even after this, if you want to give it a try, here are some of our best picks.

Flex Seal Tape

On the official page of Flex tape, it is mentioned that they haven’t been tested for use in water. This means they are not safe to be used in water. It releases chemicals not safe for human consumption along with fish. 

So, is Flex Seal tape safe for fish?

There is no flex seal tape. The only available type is flex tape.

Flex Seal products are in another liquid form which is known as the Flex Seal Liquid. This product is officially safe for aquarium use once it is fully dry.

People mostly get confused between flex tape and flex seal liquid. This misunderstanding leads to them thinking that flex tape is safe for aquarium use. But it is not true.

So, Is Duct Tape Actually Safe for Fish?

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No, duct Tape is not actually safe for fish.

To some extent, all types of duct tapes are unsafe for fish. The Polythene in duct tapes is made up of polymer. This has repetitive units of ethylene with additional monomers having difficult structures.

Also, there’s a huge effect of the monomer. They make up the ultimate compound and it comes to plastic toxicity. 

Duct tape also consists of low-density polyethylene. It is moderately toxic when inhaled or ingested in a large amount.

Polyethylene is used for food-grade use. Such as in the packaging of beverages and packed food. They have no risk of being toxic when exposed.

These are not harmful for use as much as duct tape polythenes. But both would have a mechanical effect when ingested as microplastics on the fish’s biology. 

Are There Any Better Alternatives?

The safest glues and silicones to use in aquariums are non-toxic glues and silicones. They are specifically designed for aquarium use. Make sure any adhesive or silicone you use is appropriate before using it.

If you’re not sure, don’t use it. You can ask your local aquarium shop for advice. XFasten Silicone Tape is one of the best for this use.

Super glue gels are waterproof and safe for aquarium use. The base ingredient in it is ethyl cyanoacrylate. Most super glue gels get off with time when immersed in water.

So, you won’t notice any hazardous consequences as long as you don’t use a lot of glue in your aquarium. Super glue can be used for more than simply fragging corals.

It can also be used to make frag racks, repair broken equipment, and bond small pebbles together. If you want one for purposes like these, here’s the best one to use.

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Hot glue guns are also safe for use underwater as they do not have any toxic elements. The polymers in it are reef safe when cooled properly. It has zero aquatic toxicity as per the ingredients list.

But you need to be careful to check the packaging if any extra color or wax has been added. Nonetheless, its bonding strength is not that holding for aquarium use.

To give the adhesive something to stay into and hold, you need to rough up each joining surface. This can be done with a sandpaper. So, you can buy 3M Aluminum Oxide Sandpaper or an Exacto-Knife.

Significant glass cracks need a tank change. The bulk of hot glue adhesives is used to make a temporary fix for a broken part until a new one arrives. But the best solution would be to use silicone glue or superglue if available in the place.


What adhesive is safe for fish?

Silicon glue is the safest adhesive for fish. The most often used aquarium-safe adhesives are cyanoacrylate Super Glue and pure silicone. Aquarium-safe silicone sealants are also considered reliable remedies for ornaments and tank cracks. It stops any leakage most efficiently.

Is Gorilla Glue Waterproof?

Gorilla Glue is a waterproof glue. It can be used both indoors and outdoors and is strong enough to withstand the elements. Roughen up bright surfaces, such as metals, glass, and some plastics. So the glue has something to bite into.


That is all from us on is duct tape safe for fish. As you have come this far, we have an added tip just for you.

Many people who have used Teflon tape claim it to be aquarium safe. They say that they have used it and saw no harm to their fishes. So, if you find nothing else, you can give it a try as they contain no toxins. 

Before we end, do you have any queries? Let us know in the comment section below. Till then, we wish you a good day!

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