TCMAS : Articles : Aquascaping Your Tank - Part 2

Aquascaping Techniques - February 24, 2006 Demo - By David Grigor

Tools Needed:

• 1. Fiberglass rods: They are used to put reflectors on at the edge of your driveways etc. They can be found year round here in MN at Home Depot or Menards. Usually orange in color. Cost about 2-2.50 per rod. Get 3-4 of them. What you don’t use can return to the store later. They are usually found on the isle near the mailboxes and house numbers. I have found Meanards to be cheaper than Home Depot. The fiberglass rod is preferred over acrylic rod because it is slightly smaller than 3/8” so easier to slide into rock and is more rigid.

• 2. 3/8” Acrylic rods & scrap ¼” or thicker acrylic, Weldon #3 acrylic cement: Use to make acrylic stands for the base of the structures. This is optional.

• 3. 3/8” Drill: Use the cheapest drill you can find. You can find Menards house brand or other no-name drills at harbor freight for $10. Hammer drill option can be handy for more stubborn rock but not required. Not recommended to use cordless because saltwater can easily short out the battery and ruin it.

• 4. 3/8” Concrete Drill Bit: I prefer the Bosch concrete bit it runs about $12. You can use masonary bits but the concrete one drills easier and less likely to split the rock when drilling because doesn’t require as much pressure.

• 5. Tarp or plastic liner: to put your rock on to visably see the shapes and sizes to choose from. Also, will be use to drill your rock as to not make a mess on the floor.

• 6. Dremel tool with fiberglass cut-off wheel: Makes it easy to cut the fiberglass rods. For the final touches makes it easier to snip to rods close to the rock.

• 7. Scrap Plywood or studs: To place under the rock as to not drill through the rock and damage the floor or carpet.

• 8. Rubble Rock: Optional but recommended to put in the seams and help hide the rock.

• 9. Harvey’s Epoxy Plumbers Putty: Sold at Menards and Home Depot about $5 a stick. Used to firm up seams and camoflouge the rods. Portland Cement, Crushed Coral, aragonite sand: Optional, discussed in the finishing steps. To firm up and camoflouge the rods. Only need a couple cups of each.

• 1. On a piece of paper draw a general sketch of what you would like. See Figure #2. With this technique you can pretty much build to your plan. Of course there may be some improvising as you're doing it but it is good to have a plan in place.

In my example: I will be building a large arch on the left. An arch that slopes on the right and a freestanding off balance structure in the center.

• 2. Build some acrylic stands to add stability to your structure and will give you greater flexibility in making offset structures that would otherwise not be possible. If you decide to skip this step you will need to have some pretty sturdy and nice sized rocks to use as base for your structures. If you are planning any kind of sand bed deep or shallow where the acrylic stands will be totally hidden this is highly recommended. Scrap acrylic can be bought by the pound for approx. $1 so this is not very expensive. 3/8” Acrylic rod is also sold by the foot but should only cost a few dollars. Cut some scrap acrylic into approx. 8X8 sizes. Drill a 3/8” hole in the center. Snip off approx. 5” length of acrylic rod. Use Weldon #3 to secure. Lay out the tarp in front of the tank.


A. Drill 3/8” hole in the center.
B. Snip off appox. 3-5” length of the acrylic rod.
C. Use Weldon #3 to secure.
D. Cut some scrap acrylic into approx. 8X8 sizes. Drill 3/8” hole in the center.

• 3. Using a piece of electrical tape, I like to mark on the tank a measurement of approx. 2/3 the height of the tank as a guildline so that you don’t built the structure too tall. Also it’s not a bad idea to have a tape measure nearby when building your structure outside the tank so you know how high to build the structure.

• 4. Drain the tank. This is optional but HIGHLY recommended. This will actually save you time, will be less messy, will make your structure more visable, and easier to do the final touches when adding the putty to the seams. If you're doing just a partial rework of your aquascaping with livestock in the tank it may make sense to work with water in the tank. Not recommended when upgraded tanks.

• 5. Have your LR in a tub nearby. You will want to lay out your rock on the tarp so you can see what pieces you have to choose from for size and shape.

• 6. When drilling be sure to have a piece of plywood or studs so you don’t damage the floor.

• 7. It is recommended to have a partner around as an extra pair of hands. The more of the scruture you can lift into the tank without taking apart the better because sometimes it’s not easy to figure out how you had it the first time.

There are endless possiblities. Below are a few of the more popular shapes/designs. Be creative. As you get done with a structure outside the tank. Try to place the rock in the tank as assembled as possible. This is where an extra pair of hands comes in handy.

My personal preference is to be sure not to get too close to any of the tank walls so that if needed I can reach all areas of the tank in case of a fallen coral. I also like to keep clearance in the back as well so that I can clean and scrape the back wall of coraline. At the minimum you will want to make sure there is clearance for glass magnets or to manually scrape the glass.

While you're building the next structures it’s a good idea to, every 5 or 10 minutes, pour water on the LR that is now in the tank to keep it from drying out as much as possible. As long as your LR is not out of the water for more than a few hours and not allowed to completely dry out, you should not need to re-cure the rock. I do however as a safety measure add some bio-zyme to the water for the first 3 to 5 days as a precautionary measure. This is especially key if you will be placing livestock back into the tank immediately. I have never had a major issue but best to play it safe.

The Arch:

Cut 2 pieces of rod to work with using the dremel, it should be a little larger than you need. When you are finished you can snip off the extra. I recommend to drill the rock with the angle that is respective to what side of the arch you are making. Don’t worry or analyze to much the angle. Remember you can always drill a new hole and once on the rod you can turn the rocks until the lock into best position and to help hide the rods. In the final steps, you will be covering the rods with putty and rubble rock so don’t be too worried if the rods show some. Build both ends of the arch separate. Because of the angle the both ends will naturally lean to the center. Then use a good sized rock for the very top to hold them together. Use epoxy putty to secure the top rock.

The Off-balance Structure:

I typically just drill rock straight down with no angles. If you have some more plating type rock, drill the hole off center. It’s also recommended to drill some holes horizontally to mount rocks off the side of your structure to add more areas for attaching corals. This structure it is highly recommended to use the acrylic stand method so you don’t have to be as careful with keeping it balanced and can make some interesting shapes.

The Slope:

I really like to have some nice slopes in the tank. It makes a very nice display for the corals. I like to build straight up a structure from the back corner, again acrylic stand will make this more sturdy. Then either drill rocks at an angle much like the slope or just drill then straight and lean the finished structure against the stright structure in the corner.

Additional Ledges:

Feel free once the main structures are built to add horizontal holes to place rocks for more surface area and/or pre-drill holes to make mounting coral colonies on the sides of the structure easier.

There are two options. Using epoxy putty and rubble rock to firm up the rocks or the acrocrete method. The acrocrete method is used to create structures when the tank is new and the rock still has to cure for a few weeks anyways. Also because it does have to let sit for several hours to cure, this is not the best way for when your upgrading tanks and you have livestock you want to add right away.

Epoxy method:

This method is easiest and best to do before you add the water back to the tank. The rods are more visable and hand/eye cordination is better without the water. Also, expoxy seems to set better out of the waterThe putty takes kneading for a minute or two then place it in the crackes or over the exposed rods to camoflouge them. While coraline will encrust on the epoxy eventually, it is recommended if you have rubble rock to place some of it in the expoxy before it sets. This will add texture and help cover the gray color.

Acrocrete method:

I really like this method but very few people actually use it. This is really good solution for new tanks when you are going to let the LR cure. It does increase the PH levels in your tank for a while but because we are using very little and only filling in the joints it isn’t enough to be of a big concern. The biggest pro to this method is that you can really make the rockwork look seamless. It will be very difficult to tell where one rock ends and the next begins once coraline is growing on it. I like to mix small batches at a time. Mix some portland cement, crush coral, and aragonite sand ( such as Southdown ) together with some water. I don’t really have a recipe for the different elements I just mix until it is somewhat the consistency I’m looking for. Generally the acrocrete when cured is not so firm that it can’t be broken apart if you decide to reuse your rock for a new or another tank upgrade. It usually crumbs with some force. Once you have filled in the joints, you want to moisten the LR to minimize the amount of die off. I like to soak terry towels in saltwater to lay over the structures. Also good idea to cover the tank with glass covers or plastics to keep moisture in. Do this at night, and then in the morning it should be set and ready to add water back to the tank.

Remember that your aquascaping doesn’t have to fill the entire tank. By using this method you can mount your corals horizontally on the sides and ends.Seee figure #7. You can always add rock in between the different structures to fill it out more if you wish. Once yor structure is stable you can use the stacking method with putty. I personally like to keep the different scrtucture distinct but some people like to add more rock. You can pre-drill some holes in the rock to make mounting corals easier. With pre-drilled holes, it you wish can mount frags that are on plugs directly to the scructure and until they have fully encrusted you can plug and play with the locations that work best for the coral.

David Grigor

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