Aquarium Glue for Plants: A Comprehensive Guide

Aquascaping is both an art and a science. Creating a beautifully arranged underwater garden takes patience, precision, and the right tools. A reliable aquarium-safe adhesive is one of the most important tools for any aquascaper. Gluing aquatic plants and decor in place is crucial for maintaining your hard work and vision.

But with so many options on the market, how do you choose? Not all glues are created equal regarding the unique demands of an underwater environment. In this comprehensive guide, we’ll explore the pros and cons of various aquarium plant glues so you can make an informed decision. We’ll also cover proper usage and application techniques to turn you into a first-rate aquatic plant gluer.

So grab your pruners and let’s get sticking!

Types of Aquarium Glue

When it comes to adhesives for use in aquariums, there are three main types:

Cyanoacrylate Gel

Cyanoacrylate gel, commonly known as “super glue gel,” is the most popular and versatile option for aquarium use. This adhesive comes in easy-to-use tubes or bottles and dries quickly. It bonds firmly to smooth surfaces like rocks, driftwood, and plastics.


  • Specifically designed for underwater use
  • Bonds rapidly
  • Convenient application
  • Affordable pricing
  • Can be used on a variety of materials


  • Can leave white residue
  • Not as effective on porous surfaces
  • Limited usefulness for repairs/sealing

Silicone Sealant

Silicone sealant, typically available in squeezable tubes, is the adhesive for sealing aquariums and repairing leaks. Unlike cyanoacrylate, it remains flexible when dry and adheres well to glass. Silicone can also be used to attach decorations or fill gaps.


  • Strong, flexible bond
  • Won’t become brittle over time
  • Excellent for sealing tanks
  • Useful for repairs
  • Can adhere decorations


  • Not ideal for delicate plants
  • Slow drying time
  • Can be messy to apply

Specialty Aquarium Glues

Some “luxury” glues are marketed specifically for use in planted aquariums. These are cyanoacrylate gel formulas, but packaged differently under specialty brand names. They usually offer no significant advantages over basic super glue gel.


  • Specifically designed for aquarium use
  • Often thicker gel consistency


  • Very expensive
  • No major benefit over cyanoacrylate

Comparing Major Brands

Now let’s take a look at some of the major players in the aquarium adhesive market:

  • Loctite Super Glue Gel: The OG of aquarium plant glues. This budget-friendly cyanoacrylate gel dries quickly and bonds most decorative materials. It leaves a white residue if applied poorly.
  • Seachem Flourish Glue: A specialty aquarium glue with a premium price tag. It has a thicker gel formula for easier application but doesn’t offer increased bonding strength.
  • Gorilla Super Glue Gel: The classic high-strength cyanoacrylate formula. It will stick anything to anything but is not specifically designed for underwater use.
  • GE Silicone I Sealant: The silicone of choice for sealing glass aquariums. It remains permanently flexible and won’t break down over time. Great for repairs but not for plant attachment.
  • AQUAfix: A cyanoacrylate-based German specialty brand aquarium glue. Offers precision application but has limited availability outside Europe.

Is Gorilla Glue Safe for Aquariums?

Given its incredible bonding power, Gorilla Glue seems like an ideal aquarium adhesive. However, most Gorilla Glue formulas contain isocyanates, which can leach toxins into the water.

Only the clear Gorilla Glue Gel is suitable for aquarium use. Other varieties like the classic tan Gorilla Glue contain toxic compounds and should never be used in aquariums. Always check product labels to ensure safety.

When in doubt, opt for cyanoacrylate gels specifically designed for underwater use, like Loctite Super Glue Gel. Don’t take risks with your aquatic pets and plants.

Tips for Using Cyanoacrylate Gel

Cyanoacrylate gel aquarium glues offer unparalleled versatility and bonding power for the price. Here are some tips for getting the most out of these super glues underwater:

  • Use sparingly: A little dab will do ya. Too much glue can leave unsightly white residue.
  • Apply to clean surfaces: Remove debris, algae, etc. for optimal adhesion.
  • Press firmly: Smush those plants onto the surface while the glue dries.
  • Let dry fully: Resist the urge to reposition for at least 5 minutes.
  • Trim carefully: Dried glue can be trimmed away, but be cautious of plant roots.

With good technique, cyanoacrylate gel will secure decorations and allow you to create a flawless aquascape.

Gluing Aquatic Moss: Technique Matters

Aquatic moss like Java moss is extremely popular in planted aquariums for its decorative effect. But its fine strands and delicate leaves can make glue difficult. Here are some tips:

  • Apply glue to hardscape first, then press on moss. This prevents visible residue.
  • Use porous rocks or driftwood. Moss attaches better to uneven surfaces with crevices vs smooth plastic or glass.
  • Sand down rough edges on decor to prevent snagging.
  • Let dry longer, 15-20 minutes. Gel remains slightly flexible when bonding moss.
  • Be gentle when planting around glued moss to avoid uprooting.

With extra care, cyanoacrylate gel will keep unruly moss in place. Java moss walls and carpets can become a reality!

Securing Driftwood in Aquariums

Driftwood adds a dramatic, naturalistic element to planted tanks. But getting those gnarled branches to stay put can be frustrating. Here are some tips:

  • Choose dense woods like mopani that will sink readily. Avoid buoyant varieties.
  • Soak before use to waterlog and saturate porous wood.
  • Weigh down temporarily with rock or other decor while glue dries.
  • Apply glue generously on contact points between wood and substrate.
  • Allow extra drying time, at least 1-2 hours. Porous woods absorb glue.
  • Reinforce with zip ties and fishing line if needed for heavy pieces.

Even the most unruly driftwood can be tamed with patience and plenty of cyanoacrylate gel.

Attaching Plants to Rocks or Driftwood

Creating a lush planted aquascape requires securely attaching plants to hardscape materials like rock and driftwood. Follow these steps for success:

Prepare the Surface

Scrub rocks or wood with a brush to remove debris. This allows for optimal glue adhesion.

Choose Suitable Plants

Hearty varieties with rooted growth like anubias and java fern attach better than delicate stem plants.

Apply the Glue

Put a small dab of cyanoacrylate gel on the attachment point. Too much looks sloppy.

Affix the Plant

Press the plant rhizome or roots firmly into the glue. Hold 30 seconds until set.

Let Dry

Leave the plant undisturbed for at least 5-10 minutes to fully cure. Give stems extra support.

Trim Excess Glue

Carefully trim any dried glue blobs with sharp scissors or a blade. Avoid damaging roots.

With good technique, your plants will effortlessly adhere to hardscape materials, allowing you to create a naturalistic underwater haven.

Fixing Decorations: What’s the Best Glue?

Over time, the bumps and jostles of aquarium life may cause decorations to come unglued. Repairing broken ornaments or attaching new ones is easy with cyanoacrylate gel. For ornaments:

  • Remove from the tank and let dry fully before gluing
  • Roughen smooth surfaces like plastic or resin with sandpaper for better grip
  • Apply glue sparingly to avoid residue
  • Clamp pieces together using clothespins while glue sets
  • Let cure overnight before re-submerging

Using cyanoacrylate gel, strong, long-lasting bonds can be achieved with most ornament materials. Just avoid glue clouding the water when you return decorations to the tank.

Using Silicone Sealant in Aquariums

While not ideal for gluing plants, silicone sealant has several indispensable purposes in aquarium maintenance:

Sealing New Tanks

  • Use clear, 100% silicone sealant like GE Silicone I to seal all joints in new glass tanks before adding water. Allow to cure fully, at least 24 hours.
  • Check manufacturer instructions to determine the recommended bead size and application method. Avoid messy applications.
  • Ensure a smooth, consistent seal without gaps or air bubbles. This prevents future leaks.

Repairing Leaks

  • First fully drain the leaking tank and allow glass to dry thoroughly. Identify source of leak.
  • Thoroughly clean and sand damaged area to create a good surface for sealing.
  • Apply fresh silicone sealant over the damaged, leaky area and spread evenly. Allow to fully cure before refilling.
  • For minor leaks, you can apply silicone with tank half-full. Relieve pressure by placing a plastic bag of tank water inside to offset water weight.

Re-Securing Decorations

  • For decor items that won’t adhere well with cyanoacrylate gel, use silicone as an alternative. Go sparingly.
  • Let silicone cure fully before submerging, at least 24 hours. It will remain flexible to allow for natural movement.
  • Be aware silicone can be difficult to remove later if you want to adjust decoration placement.

Filling Background Gaps

  • Use clear silicone to fill any unsightly gaps behind tank backgrounds and around fixtures.
  • Apply neatly with a disposable craft stick or silicone shaping tool for a clean finish.
  • Match silicone color to background for nearly invisible repairs. Black backgrounds hide silicone especially well.

With the right technique, silicone sealant can make aquarium setup, repairs, and decorating a cinch while keeping your tank watertight.

Alternative Plant Attachment Methods

While glue is the go-to for securing aquarium plants, you also have a few other more temporary options:

Plant Weights

  • Lead plant weights available at aquarium stores can anchor plants to the substrate. Useful for newly planted stems.
  • Add a small pebble or aquarium-safe putty to weigh down delicate plants until their root system establishes.

Fishing Line/Cotton Thread

  • Use thin fishing line or cotton thread to tie plants to decor gently. The line will eventually decompose.
  • This offers a non-permanent attachment option and avoids glue residue.

Planting Directly in Substrate

  • Plants like swords and crypts can root directly into the substrate. Ensure a deep, dense substrate bed.
  • Gently bury roots and rhizomes while minimizing uprooting of other plants around them.

FAQs About Aquarium Glues

How long does it take for aquarium glue to dry?

Cyanoacrylate gel glues set rapidly, within 2-5 minutes generally. Allow 10-15 minutes for a full cure. Go longer for porous materials like moss and driftwood.

Is super glue toxic to fish?

Cyanoacrylate gel is non-toxic when fully cured. Avoid using runny “liquid” super glues – these can leave residue.

Should I attach Anubias and Java Fern to driftwood or rocks?

Yes, anchoring the rhizome of these broadleaf plants prevents rotting that can occur when burying them.

What’s best for attaching moss—super glue or sewing thread?

Glue for sure! Thread decomposes over time, causing the moss to detach. Super glue gel offers a long-lasting bond.

How do I remove dried glue in my tank?

Excess dried glue can be carefully trimmed off with aquarium scissors or removed by rubbing with your fingers. Avoid damaging plant roots.


Creating a beautifully arranged underwater garden takes skill—and the right glue. By understanding the strengths of various aquarium-safe adhesives, you can securely attach plants and decorations to realize your dream aquascape. Cyanoacrylate gels offer versatility at an affordable price point for bonding plants and ornamentation. Silicone sealants keep tanks watertight and allow for repairs. Follow best practices for application and curing when gluing underwater. With the right adhesive knowledge, you’ll be on your way to a jaw-dropping planted tank that perfectly sticks together.