The Best Hardscape Glue for Aquariums

At Horizon Aquatics, we always secure our aquascaping wood and rocks with glue — not only to prevent them from floating when added to the aquarium, but also to ensure they stay firmly in place during routine maintenance.

Why Use Glue in Your Aquarium?

We use glue so that wood can be used instantly, without the need for days, or even weeks of pre-soaking. By attaching wood to rocks, it becomes weighed down, allowing you to start aquascaping right away.

Which Aquarium Safe Glue to Use?

We use our own specially tested hardscape glue, which we rely on for every aquascape in our store that requires hardscape to be securely held in place. For hardscape we use the Horizon HARDCSCAPE Glue which is a liquid glue, the other gel type is for plants only. 

We also have glue precision tips which can be applied to the Hardscape glue bottle, this allows for you to drizzle glue in tricky to reach areas if gluing hardscape in position whilst in the aquarium. 

How to Use Aquarium Glue on Your Hardscape

This type of glue is designed for use while your hardscape is dry. You can bond wood to wood, wood to rock, or rock to rock. Start by selecting the pieces you want to attach, then wedge small bits of tissue between the contact points. Drizzle the glue over the tissue — this will trigger a chemical reaction that produces smoke (ensure you're in a well-ventilated area or wear a mask for safety). Within seconds, the tissue will harden, securing the hardscape pieces together. For a strong and durable hold, we recommend using at least three glue points — this way, if one joint loosens, the others will still keep everything in place.

Aquarium Hardscape Glue: Your Top Questions Answered

Is hardscape glue safe for aquariums?

Yes! Aquarium-safe cyanoacrylate glues are non-toxic to fish, shrimp, snails, and plants once cured.

How long does aquarium glue take to dry?

It usually bonds within a few seconds underwater and fully cures in 1–2 minutes.

Will the glue break down underwater over time?

No, high-quality aquarium glues are designed to stay strong and secure even with long-term submersion, we do always recommend 3 glue points as back up incase hardscape is knocked through maintenance and breaks.

Check out this YouTube video of James where he demonstrates the Hardscape Glue in Action: