ISTA Cyanoacrylate Aquarium Glue 20g

ISTA Cyanoacrylate Aquarium Glue 20g UK: Coral Frag and Aquascaping Glue with Extender Nozzles

You have a fresh frag in one hand, a plug in the other, and a tube of glue that has dried solid since you last used it.

Most reefers buy tiny tubes that run out halfway through a fragging session, or a blunt nozzle that puts glue everywhere except where it is needed. Frags that are not fixed properly get knocked off by a snail overnight and end up lost behind the rockwork.

ISTA Cyanoacrylate Adhesive is a 20g bottle of liquid ethyl cyanoacrylate made for aquarium use, with two fine extender nozzles for placing a small drop exactly where you want it. It bonds coral frags, rock, wood and plants, works in marine and freshwater tanks, and can be used wet or dry.

Picture a rack of frags that are all still on their plugs a week later, encrusting and settled.

I have been culturing live marine food in Wales since 2008, with 18+ years in marine aquaculture, and I am happy to advise on fragging and mounting corals.

Fix it once, and let the coral get on with growing.

ISTA Cyanoacrylate Aquarium Glue: What It Is

Cyanoacrylate is the same family of adhesive as household superglue, and it is the standard way reef keepers fix coral frags to plugs and rock. ISTA make this one specifically for aquarium use. It is a clear liquid ethyl cyanoacrylate in a 20g bottle, which is a lot more glue than the small 3g to 5g tubes most of us start with. Once cured it is safe for fish, corals and invertebrates, and it can be used in both marine and freshwater tanks.

Why the Extender Nozzles Matter

The pack includes two fine extender nozzles that push onto the bottle tip. They let you reach into a gap in the rockwork, or put a single small drop on the base of a frag, instead of flooding the plug. Using less glue is tidier, it sets faster, and it makes the bottle last. If one nozzle blocks, you have a spare.

How to Glue a Coral Frag

For the cleanest bond, work out of the water. Pat the base of the frag and the top of the plug dry with a piece of kitchen towel, add a small drop of glue to the plug, press the frag in place and hold it still for a few seconds. Dip it in a cup of tank water to skin the glue over, then return it to the tank. Cyanoacrylate turns white where it meets water. That is normal, and coralline algae and coral tissue grow over it in time.

The glue also works under water for quick repairs, but because this is a liquid and not a gel, it is easier to control when you apply it above the surface. For aquascaping, it holds plants such as Anubias and mosses to wood and stone, and fixes small pieces of rock or wood together.

Glue or Epoxy: Which Do You Need?

Glue is for small, light jobs where you want a fast bond, such as frags on plugs or plants on wood. For heavier rockwork, or for filling a gap between two pieces of rock, a putty such as D-D Aquascape Epoxy does a better job. Many keepers use both together, with glue for the instant grab and epoxy for the strength.

If you are setting up for a fragging session, our Transparent Coral Frag Plugs and Coral Grow Out Discs give you something to mount onto, and the Hexagonal Mushroom Basket holds soft corals that will not take glue until they attach on their own.

Using and Storing It Safely

Cyanoacrylate bonds skin in seconds. Keep it away from your eyes and mouth, do not squeeze the bottle towards your face when clearing a nozzle, and keep it out of reach of children. Wipe the tip, replace the cap firmly after each use, and store the bottle upright somewhere cool and dry. The label gives a shelf life of 24 months at 25°C.

ISTA Aquarium Glue FAQ

Is it reef safe?

Yes. It is made for aquarium use and is safe for fish, corals and invertebrates once cured, in marine and freshwater tanks.

Is it a gel or a liquid?

It is a liquid. That is why the extender nozzles are useful, because they let you place a small, controlled drop.

Can I use it under water?

Yes, it can be used wet or dry. You will get a neater bond on frags if you glue them out of the water and then return them to the tank.

Why has the glue gone white?

Cyanoacrylate turns white when it cures in contact with water. It is harmless and gets covered over as the coral encrusts.

What is in the pack?

One 20g bottle of ISTA Cyanoacrylate Adhesive and two extender nozzles.

If you are not sure how to mount a particular coral, get in touch. Darren responds personally.