Best Aquarium Safe Glue

Published on July 15, 2019
Best Aquarium Safe Glue

It's frustrating trying to keep your aquarium plants in place. The minute you get back after fixing them, they’re already floating around the aquarium all over again.

Trust me; we understand what you’re going through here. These plants are meant to make your tank look more pleasing, so seeing them scattered all over the surface of the tank is heartbreaking, for sure.

If you’re one of the tank owners who try to keep these plants in place using weights or strings, you need to stop it right now. It’s time you switch to a more permanent solution which is using aquarium-safe glue for plants.

We know glues are pretty toxic for aquatic habitats, so we’ve rounded up the types of aquarium safe glue you could use.

Characteristics of an Aquarium Safe Glue for Plants

You would encounter a lot of adhesive products on the internet when you look up aquarium safe glue. However, they are not always 100% tank-friendly.

Now, you might be wondering what an aquarium-safe glue for plants is really like. We found the essential characteristics you should check:

Inert in Moisture or Wet Surface

You have to make sure that the glue you pick is going to withstand the water. Sure, most products that will appear in your search engine proclaim themselves safe for aquarium use.

However, you have to check how well they deal with the underwater environment. Make sure that the glue you pick is inert in moisture or wet surface.

You can measure its inertness by checking how quickly it polymerizes or changes into a harder substance when in contact with water. It takes an average of 30-45 seconds, so once you see any number within this interval, you’re guaranteed to have a long-lasting adhesive solution.

Doesn’t Cloud up to the Tank

Many aquarium safe glue users still report clouding in their tanks when using certain glues, especially super glues. Now, that’s not healthy for your fish as aquarium safe glues still have a few chemicals that are just unpleasant for your tank environment.

Always check the reviews of the products or stick to our recommendations in the last part of this article.

What are the Aquarium Safe Glue Types?

Now that you know a couple of red flags to watch in picking an aquarium safe glue, you should also know the types of glue that are proven to be aquarium safe glue for plants. I've done intensive research and here is all the gathered information you need to compare these glue types and see which one works best for your needs.

Super Glue

Super glues are the real heroes of adhesives, and there are aquarium safe super glues available in the market (look up cyanoacrylate-based super glues). It’s a classic choice for many tank owners due to these qualities:

  • Cheap (Comes in packs for a much lower price)
  • Easy to use
  • Effective, long-lasting hold

How to use:

  • Prepare the surface to which you’re attaching the plant or ornament (take it out of the aquarium)
  • Wipe away any dirt or mold on the surface
  • Apply the aquarium safe super glue on the surface
  • Stick the plant or ornament in place on the surface
  • Apply pressure for 5 seconds to secure the attachment
  • Put the cap of the super glue back after use to prevent it from drying


Super glue may be the most popular type of adhesive for aquarium plants, but aquarium safe silicone sealants are deemed the most reliable fix for both ornaments and tank cracks. Your aquarium is held together by silicone in the first place.

Here are the advantages of using aquarium safe silicone:

  • Dries clear
  • Flexible
  • Long-lasting
  • One of the few adhesives that work well with the glass
  • Doesn’t release chemicals
  • Available in different colors

How to use:

  • Check the manual that comes with your aquarium safe silicone for the specific steps.
  • Apply the silicone on the surface (make sure the surface is dry)
  • If you’re using it to repair a leak, wait for it to cure or dry (usually up to 7 days)
  • The same applies for sticking tank ornaments onto a surface

It is evident that the reason super glues remain the favorite of many tank owners is that they dry way faster than silicone sealants. However, the wait is worth it with aquarium safe silicone as they have durable bonds and zero chemical emissions when dried.


Epoxy is not a typical aquarium safe glue, but it guarantees that you won’t deal with cloudiness in your tank. It also enables the materials attached to dry right in the water, so we’re also wondering why it’s not as hyped as the first two types.

Here are more tank uses of epoxy that will make you want to try it:

  • Repairs pipe leaks and other equipment issues
  • Bonds rocks to each other more firmly
  • Has more general purposes for other aquarium maintenance

How to use:

  • If you’re keeping corals in place, apply the epoxy on it and splash it around a container of water to remove the excess substance.
  • For other materials, apply the epoxy onto them
  • Now place the ornaments back into the tank if you joined them together
  • If not, make sure your decorations were all placed correctly on the tank’s surface as you can’t just remove their attachment given the epoxy’s strength.

Top 5 Best Aquarium Safe Glue

By now, we’ve probably educated you enough about aquarium safe glues. It’s incredible how simple underwater adhesives could differ a lot from each other, right?

To keep you thrilled, here are the best aquarium safe glues we’ve personally picked for you. They all live up to the standards of a quality aquarium safe glue for plants, and other general tank uses as well.

Check out this material-diverse selection we made for you:

Aquastick Coralline Red

This Aquastick epoxy putty landed the first spot because it covers everything you could ask for in an aquarium safe glue. It is also another proof that epoxy doesn’t get the attention it deserves compared to super glue and silicone sealants.

Here’s what we love about the Aquastick Coralline Red:

It has the color you need

Many aquarium safe glues have either dull gray colors or a very opaque texture that ruins the whole look of the ornament you’re trying to keep in place. Aquastick has different colors that match corals, algae, etc.

This red one, for instance, is one of the most bought Aquastick epoxy putties because it blends well with most corals and live rock. It’s nice to know your adhesive won’t reveal you're being an amateur in gluing things together!

Hardens fast

This Aquastick epoxy putty hardens a rock quickly, unlike most aquarium safe glues. Ordinary aquarium safe glues don’t even guarantee secure attachment of stones.

Easy to use

This epoxy putty is stick-free. Of course, we don’t mean it’s stick-free in a way it doesn’t stick to the materials you want to be attached.

It’s just doesn’t stick to places you don’t want it to be like on your fingers. Once you have applied the product, it also starts holding the materials together in just 30 minutes.

It is best to wait 12 hours for it to cure though completely. This way, you can ensure that when you place the ornament back into the tank, the epoxy will not emit any chemical.

Seachem Reef Glue Cyanoacrylate Gel

We only have one reason why this product is second on this list, and that is because it’s the cyanoacrylate god of all super glues. It has all the good qualities of a super glue plus the fact that it only takes a few seconds for it to bond anything underwater.

Here are its other qualities that won us:

Zero mess application

We all know how messy using super glue is. They stick to your fingers, and they are just not that flexible, so they stick wherever they land right away.

Seachem’s use of cyanoacrylate in their formula prevents all of those inconveniences from happening. It also makes it effortless to apply the aquarium safe glue for plants, for instance, to not look odd on the surface they are placed on.

Thicker than most aquarium safe glues

At first, we also thought that the thickness of this formula might be a red flag. Upon reviewing it further, we realized that the thickness doesn’t affect the super glue’s clean finish.

It’s a gel, so the formula is clear although its hold seems like it’s a darkened aquarium safe glue.

Doesn’t dry up in the tube

We all love how a super glue can fix everything, but after some time, it just dries up on its own, which makes us love it less. Seachem wants you to love super glue 100%, making this product resistant to drying in its tube.

So you can use it multiple times even though the product already comes in a pack of three. Definitely worth the money, right?

SILA-SEAL Clear Professional Grade

If you thought a pack of three super glue is the best we could give, here’s a case of 12 aquarium safe silicone sealants. Maybe you are wondering why you need a case of these silicone sealants, so here are the characteristics of the product that will convince you to stock up:

Tough and flexible

This silicone cures in a solid rubbery form when exposed to air. This way, you can ensure that it holds the objects you’re sealing together firmly.

Its flexibility also prevents it from slumping or forming little bubbles that mess it all up.


Aquarium safe silicone sealants last long but what we love about this particular product is that it can endure 450F for extended periods. We know how crucial temperatures are in aquarium keeping, so this product gave us a strong impression.

Safe for Food Contact Once Cured

One of the worries tank owners have in using chemical solutions is how it would affect the fish and their food inside the aquarium. We discovered that SILA-SEAL has an NSF 51 certification.

This means once the formula is cured and thoroughly cleansed, owners don’t need to worry about the food being contaminated at all. The product also comes with reclosable nozzles to avoid excessive application of the formula on the tank ornaments.

MarineLand Silicone Squeeze Tube

No matter how we searched for different materials for an aquarium safe glue for plants, our last part of the list still ended up with aquarium safe silicone sealants. Like we said in the previous section, it’s what holds the walls of the aquarium in the first place.

This product is not your ordinary aquarium safe glue. It is Caulk, so it remains flexible even in contact with water.

What we love about caulk silicone is that it is the best in fixing glass cracks and broken ornaments. Most of the aquarium safe glues above are more into just keeping things in place, unlike this one that works well in joining things back together.

Here are more qualities we admire about this aquarium safe silicone caulk:

Cheap fix

Among the other products we’ve rounded up here, this seems to be the most reasonable for its value. It also comes in different sizes (1 ounce, 3 ounces, and 10.3 ounces) so you can purchase the amount you need at the time.

Mends broken glass like it wasn’t damaged at all

This is the value we’re talking about what you get for such an affordable price. Most silicone sealants can repair broken tank glasses but in a way that it was mended.

For some reason, this brand has a trick that makes the glass look brand new and even more efficient to use than the original glass ever could. We got so curious about this, and eventually, we found many real stories of users’ experiences.

We couldn’t believe at first how many of them fixed a damaged glass just by this affordable product. Still, we put it in fourth place because it doesn’t work that well in keeping ornaments in place due to its texture.

Aqueon Silicone Clear

This is one of the easiest to use aquarium safe silicone sealants in the market that works just as effective as any other aquarium safe glue for plants. What drew us the most to this product is the fact that it is clear so you wouldn’t be bothered by it making chunks around the ornaments you’re gluing.

Here are other good qualities that might make you wonder why this landed the bottom spot (spoiler alert: we’ll reveal the main reason why):

Permanent seal

Many tank owners use this product to repair leaks in the aquarium. That’s how durable this aquarium safe silicone is.

So if you are looking for an easy-to-apply permanent solution to your aquarium’s leaks or glass cracks, here’s a reliable one.

Does not crack or shrink

Many aquarium safe silicone sealants crack or shrink after application, especially when it starts getting in contact with water. This brand is resistant to these things, so the formula remains the way you applied it after its 2-week curing period.

That’s the downside of this product--it’s long curing process. Two weeks is a lot more than the average curing periods of the other products here that are mostly just a matter of hours.

If you don’t mind waiting that long, this is still one of the best aquarium safe glues out there.

Now whether you’re just trying to keep your plants in their proper places or looking for a solution for leaks, aquarium safe glue or aquarium safe silicone sealants and caulks are the best fix. I hope that this article can convince you that there is no harm in using these formulas in maintaining your aquarium.

Our last tip for you is to pick the aquarium safe glue that fits your needs perfectly. The selection of aquarium safe glue products we made for you are meant to serve different purposes, and we’re sure you’ll find the right match with one of them.

We even found more than one match from that list for our tank needs!

One comment on “Best Aquarium Safe Glue”

  1. Good you,l'm think about using pices of slate glue to a piece of concrete backer board then guleing the board to the glass. First after measuring and cutting the board 1.5" smaller than the tank,letting it soak in some water to get the ph down, letting it dry,rinse the rocks, mayde using some sand paper on the back so the silicone can gripe better,or maybe use some epoxy or reef glue ,using the Professional Grade RVT SILICONE......

    JONES. J.F.,U.S.M.C
    P.s Or some 3m 5200 Gule

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