Can You Use Scotch Tape in a Fish Tank?

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Every fishkeeper faces the problem of a leaking aquarium or moving things inside their tank at some point.

It can be annoying and poses a safety risk for the fish. Sometimes, using an adhesive feels like a great temporary fix to deal with the issue.

Using tape to attach the accessories inside the tank may seem like an easy option, which is why so many aquarists default to this technique.

However, the real question is if scotch tapes are safe for use in an aquarium. 

Most importantly, is scotch tape effective in an aquatic setup or will it simply take on water and lose its grip over time? Without further ado, let us jump right into the topic.

Is Scotch Tape Toxic for Fish?

Manufactured by the brand 3M, scotch tape is a pressure-sensitive tape. 3M uses 65% recycled or plant-based material, making it one of the safe and most eco-friendly tapes available on the market.

Even though the packaging of your scotch tape is 100% recycled cardboard, it is an eco-conscious choice for buyers and users alike.

It is certainly not toxic for fish, invertebrates, or aquatic plants, making it a safe choice for your tank. 

Is Scotch Tape Waterproof?

Scotch tapes withstand moderate moisture but only for a short duration. They cannot hold through prolonged exposure to water. 3M even says that storing scotch tape in damp areas can be risky.

Unfortunately, you cannot use scotch tape to conceal a leak from within the tank or fix things to the bottom of the tank. However, you can try using it as a temporary fix until you find a more permanent solution.

Can You Use Scotch Tape Under Water?

Scotch tapes are not waterproof. They cannot work as an adhesive under water or in an aquarium setup. You may use Teflon tape to tackle the situation temporarily.

The Teflon tape may or may not work, depending upon the weight of the tank or accessories you are trying to bind together.

Aquarium Safe Tapes

There are a few non-toxic adhesive options for aquariums. Cyanoacrylate Super Glue and pure silicone are two of the most common aquarium-safe adhesives used by fish keepers to fix leaks and affix accessories to the bottom of the tank.

Other options include super glue, silicone, cement, and hot melt glue. 

Super glue can work as an effective adhesive for bonding coral fragments to ceramic plugs or bases.

When you go to the store looking for non-toxic glues for your aquarium, search for products that use ETHYL CYANOACRYLATE as the base ingredient.

Best Alternatives for Tapes in Fish Tank

Thanks to a bunch of scientific advancements in the field, there are several other alternatives to scotch tape.

Let me introduce you to a world of non-toxic adhesives that are also safe for your little finned friends:

– Bondic

Bondic is a welcomed newcomer in the Super Glue market. It is a liquid-based plastic oligomer that flows like a regular adhesive until you expose it to UV light. UV light hardens the liquid in seconds, turning it into solid plastic.

It works great for sealing cracks in your tank, mounting coral frags inside the aquarium, etc. However, you must cure it fast to ensure the accessories stay in place.

Bondic comes with a built-in UV LED, which secures your accessories inside the tank within seconds. Bondic adhesive system is widely available in most hardware stores. The best part about buying a bondic is that you can easily find the necessary refills on Amazon.

– Aquarium Safe Silicones

Silicone is a significant component in building glass aquariums. Aquarium manufacturers generally use silicone to join all the seams in a glass tank thanks to the material’s incredible bonding capabilities.

Some aquarists even try their hand at building a customized glass aquarium using silicone. In fact, silicone is the only product designed to glue glass, making it ideal for aquarium use. 

However, make sure your silicone product is 100% pure silicone before buying it. Some silicone adhesives can contain additives, which can turn the material toxic for your tank inhabitants.

Read the label and make sure it is toxin-free and mildew resistant, mold inhibitor, bacterial protectant, and anti-microbial. Some silicones may be toxic to aquatic life, especially those in an uncured state.

Silicone adhesives are 100% safe for fish and other aquatic creatures, as long as they are free from additives and have had sufficient time to cure fully.

– Aquarium Safe Cement

Cement used in the aquarium hobby is of two types: Acrylic and PVC & ABS. Acrylic refers to sheet materials used in building tanks, sumps, and containers.

On the other hand, PVC and ABS materials are yet another non-toxic aquarium plumbing adhesives. Acrylic and PVC/ABS bonding helps melt the two joining pieces together, forming a strong bond.

The viewing windows of large aquariums are made from incredibly thick acyclic sheets. These tanks then undergo on-site bonding to create a big window.

– Teflon Tapes

Teflon or Thread seal tape is a polytetrafluoroethylene (PTFE) film tape widely used in plumbing.

These are waterproof and can help seal small or minor cracks to contain leaks temporarily.


If you’re dealing with aquarium cracks or want to secure stuff to the bottom of your tank, several non-toxic and eco-friendly adhesives can help in that regard.

While scotch tape may not be one of them, this article has opened you to a world of alternatives that are affordable, effective, and safe for aquatic animals.

If you are dealing with an aquarium emergency and need an adhesive ASAP, I recommend the Aquascape 82000 Clear Silicone Sealant, 10.1-Ounce Caulk Tube.

It is safe for fish and plants and offers the best value for your buck. Aqua cape clear silicone sealant is easy to use and is ideal for ponds, aquariums, and terrariums.

You can make professional water-tight seals in no time with this product. You can use this silicone adhesive with a caulking gun.

Author Image Fabian
I’m Fabian, aquarium fish breeder and founder of this website. I’ve been keeping fish, since I was a kid. On this blog, I share a lot of information about the aquarium hobby and various fish species that I like. Please leave a comment if you have any question.
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