BRStv Buyer's Guide To Glue, Epoxy and Mortar For Aquascaping Dry Live Rock

Aquascaping your aquarium can be both an exciting and daunting project, but with a little know-how and the right tools for the job you can build the perfect canvas to showcase your reef. Creating an aquascape is not only an essential element to building your system, but it is also a great way to express yourself and have some fun at the same time.

Ryan & Randy’s Favorites + One Option To Avoid

Ryan & Randy's favorite, in this case, is all dependant upon the job at hand. It is critical to choose the right adhesive based on the particular aquascaping job or style you plan to use. Don't worry, we define each of those scenarios below.

For now, walk away with this one bit of advice. Do not use epoxy when building your aquascape. While many reefers use epoxy to help hold rocks together, we typically do not recommend using Epoxy for a couple of reasons. Epoxy doesn’t stick very well and it will, therefore, make your structure less sturdy. Epoxy also takes forever to dry and tends to stick out and become an eyesore in your reef. Not to mention it will make your skimmer go nuts.

Best For Marco Rock: BRS Extra Thick Gel 10oz

Marco Rock is our best-selling dry rock option and in order to secure multiple pieces together, we recommend using our BRS Extra Thick Gel. The 10oz bottle is large enough to deliver plenty of glue and to ensure your structure is secure. Marco Rock tends to stack very well with all the nooks and crannies so simply gluing the touchpoints will work well. Using a popsicle stick to create a mold of glue around the attached area is a great option to keep your hands free of glue. The BRS glue dries semi-transparent, almost 100% clear, and if you need it to cure quickly our Insta-Set Glue Accelerator will have your structure secured in minutes. 

Best For Underwater: BRS Extra Thick Gel 20g

If you are gluing your aquascape underwater then small tubes of our BRS Extra Thick Gel would work best. Using the bottle underwater would cause you to suck water back into the container and thus ruining it completely. The small, single-use tubes won't suck any water back into them which makes them the best option for underwater use. Using this glue underwater creates a film that makes it workable and you can push the glue into a crevice or hole with your hands. Cyanoacrylate-based glue like this cures based on the exposure to or presence of moisture so it won't be long before a rock-solid bond is formed.  

Strongest Hold: Marco Mortar

For a gravity-defying scape or for situations where a rock needs to hold a lot of weight, there is no better option than the E-Marco-400. This mortar comes in both a standard beige rock color as well as a purple color to match your CaribSea LifeRock or Real Reef Rock. This cement will hold the best out of any adhesive option and it will bond the two rocks together creating a transition. If you want this transition to appear seamless then placing some thin glue on it and covering it with sand will do just the trick.

Best For NSA (Negative Space Aquascape): Lots Of Glue & Mortar

For the crazy arches and other rockwork that is synonymous with negative space aquascaping, you will most likely need to use a lot of bonding. Stocking up on mortar, super glue gel, and accelerant is advised, and buy more than you think you will need because you don't want to run out. The technique we use for these scapes is to secure all of the pieces with glue first, support the gravity-defying structures with books or sticks while it all cures.  The following day, go back and solidify the joints completely by covering them in eMarco Mortar. This will allow you to create a very interesting aquascape that is strong enough to last the life of your reef and support large, mature coral colonies.

The accelerant works great during that initial gluing process as it will minimize the necessary time you need to hold the rocks together using your hands. Pending the intricacy of your particular scape, by the time you're finished gluing the last rocks together, a majority of the glue will have fully cured.  If you run out of accelerant, it can often be found at your local hobby shop alongside super glue gel-type adhesives, this way you are not stuck waiting for a new bottle to ship from BRS.  The Marco Rock eMarco Mortar on the other hand is specialized and made specifically for aquascapes, so be sure you have enough on hand.

As mentioned earlier, once the mortar cures solid you can go back and coat the joints with a thin layer of super glue and spread sand or rubble on those areas to help seamlessly blend everything together. The result is pretty impressive if you take the time to do it right.    

Other Considerations

Drill & Rod

This is not a method that we like to recommend due to its difficulty. While it might seem easy enough to drill through two pieces of rock in the exact position you desire, facts are, it is not easy to execute.  The rocks always tend to shift and your better off just using the super glue gel and mortar combo, it works just as well and doesn't require precision drilling.

The one situation in which this might be useful is for stacking large pillars of rocks were positioning the rocks in a specific way is not required. In this case, you can just drill the rocks one at a time, then slide them onto a vertical acrylic rod creating a large pillar or single stack of rock. Something very unique and not all that common for home aquariums, this is more of a technique used in large public aquaria-type situations. 

Can I Use Standard Cement?

While using standard cement may be an option, it will need to cure for much longer than the E-Marco-400, and it may leach potentially harmful particles or chemicals into your system. The E-Marco-400 was specifically designed to cure underwater, is much less brittle than typical cement, and is 100% reef-safe. 

BRS Extra Thick In The 20g Tube Is The BEST! 

The smaller 20g tubes of BRS Extra Thick Super Glue gel are the smartest choice to keep on hand. This tube is great for use underwater, it is the perfect option for getting into tight spaces and it will often store properly for multiple uses if capped correctly.  One of the biggest problems with larger containers of superglue gel is they will not store all that well, especially if you get some water inside. The large 10oz bottle is great if your sitting down to use a lot of glue at once, but if you're looking for general glue to have on hand after putting water in your tank, the 20g tube is the ticket.

If you are really into fragging or find yourself using glue quite often, having multiple tubes on hand is smart. Just in case you forgot to put the cap on tightly last time or cracked the metal tube on accident, you always have a brand new tube ready to go. Even if your not using the BRS brand glue, having a few of those tiny single-use tubes of superglue gel from the craft store is the most ideal option to always ensure you have usable glue on hand.