
Aquarium enthusiasts spend a lot of time and money on their aquariums with the intent to recreate the beauty of nature.
Super glue can help you do that. But is it aquarium-safe?
Cyanoacrylate Is Absolutely Safe

There are different chemical makeups for super glue. The one you want to use in an aquarium is cyanoacrylate.
Cyano is taken from the Greek word for “blue”, and also from the medical chemical for cyanide, but is harmless when combined with -acrylate. The chemical suffix -acrylate refers to esters, ethers, and salts of acrylic acids. This is what gives the super glue its fumes and transforms the cyanide into a harmless compound. As for the fumes, those quickly dissipate as super glue dries, and they will not be present or affect your fish in your aquarium.
Uses for Aquarium Safe Super Glue
For Tank Glass Repair
The only aquarium safe super glues are made of cyanoacrylate. If you stick with these glues, your hobby and your fish will be fine. If you want a super glue for gluing chips of glass back into the tank or gluing pieces of the tank back together, you will need to follow this process:
- Empty the tank.
- Dry the tank glass thoroughly where you will be gluing things together again.
- Use a generous amount of super glue gel on the edges of the broken glass.
- Hold the pieces in place for the required ten minutes to cure.
- Avoid refilling the tank for at least thirty minutes.
- Water helps “dry” the glue once it has had time to cure outside of the tank/water.
If you are just fixing chips out of the inside of the aquarium, be sure the chipped spots are completely dry. Fill the chipped indents with super glue gel, and then press the chips of glass back into place. Let them cure before filling the tank again. Super glue gel is ideal for this as it acts as both glue and glass filler.
For Securing Live Plants to Rocks
Live plants in your aquarium keep the oxygen levels balanced so that your fish will be able to breathe and not develop any lung issues. However, live plants are tricky to get started because they are not already rooted from their seedling stage. This is why most aquarium hobbyists buy the plants as seedlings.
Without anchors in the water, the plants will slowly drift to the top of the tank. To get the plants to stay where you place them:
- Select a tank rock and dry it thoroughly.
- Gently dry the roots of the plants by dabbing them with a paper towel. To avoid damaging your plants, do not squeeze or twist the roots while drying.
- Using the aquarium safe glue you have chosen, liberally apply to the rock.
- Press the roots of the plant onto the glue. You may use cotton swabs or popsicle sticks to avoid getting glue on your fingers.
- Hold the plant to the rock for five to ten minutes.
- Sprinkle sand over the area to make the rock and the dried super glue look completely natural inside the tank.
- Place in the tank where you want it. It helps to add tank gravel on top of the rock for the first few hours until the plant is very secure.
This also works with live rock, placing plants on live rocks, or connecting live rocks and corals together. All of your live things will eventually grow together and grow over the fish tank glue, leaving no trace of it exposed.
Experimenting with Other Aquarium Safe Super Glue
You can try other aquarium-safe glues, but you may always come back to the one that really seems to do the trick. Just keep in mind that you need to read the labels on the super glues every time you shop. Standard super glues sold on hardware and craft store shelves are only safe for your fish and plants if their only active ingredient is cyanoacrylate. If you stick to that one rule, you will enjoy a lot of success with your aquarium building and fish raising.