How to make a floating reef – a tutorial

We normally don’t write in English here, but because of the great interest in this article from all over the world, we have decided to translate our guide on how to make a floating reef. This was originally written by Swiss hobbyist Dave Notter (31) for Zeewaternieuws.

Two months ago, we showed you the floating reef of Dave Notter (31). Today, the man himself explains how to create your own floating scape.

A floating rockwork can’t be made in a jiffy. It takes some time, patience and handywork. But it is perfectly possible to create your very own floating reef.

First and foremost, you’ll need some materials:

• An empty and dry reef tank
• A piece of acrylic that is sufficiently large for the rocks to hang on to
• A drill
• Sandpaper
• A hot glue gun
• A marker or sharpie
• Aquarium-safe silicone
• Dry rock
• Glue for the rocks
• A measuring tape
• A clamp or two
• Gloves
• A towel, some paper or a carpet of sorts to protect your workspace

Besides, it is important to have a piece of acrylic that is at least 5 mm (0.2 inches) thick. Silicone is not an ideal product to glue acrylic, so you’ll have to make sure that you have a large enough surface where the piece of acrylic and the aquarium glass meet. Before you start this project, it’s a good idea to clean the aquarium glass and the acrylic part thoroughly. This is to ensure that the silicone will stick to both.

1 – Bend the acrylic part

The acrylic part must be bend so as to form a 90° angle. This part will be the support for the rock-work. Take a sharpie or other marker and mark the spot where you want to bend the acrylic plate. Be sure both sides are big enough – one for the rock-work and the other to attach the plate to the glass. This acrylic plate will possibly hold a lot of weight, so be sure you have a big enough gluing area.

Put the part on the table so that your marking is on the edge of the table. Secure the plate with one or two clamps. Be sure to wear gloves, and warm the part with your heat gun, just around your marking. Do not force the acrylic part by applying pressure on it early. Just let it warm up until it is ready to bend. Proceed to bend the plate just under 90°. The weight of the rocks will further bend it later on.

2 – The holes

Once the acrylic plate has cooled, we can drill the holes. Put the plate on the table again, and drill a few holes in the part that will support the rocks. Use a correctly sized bit, depending on the project. I used a drill with a diameter of 5 cm (2 inches). Use sandpaper to clean up the edges.

The holes you just made serve two functions. First and foremost, they allow current to go behind the rocks. There will be a reduced chance of detritus accumulating behind them. On the other hand, animals may find refuge there.

3 – Assembly

Now we have the perfect base plate for our scape, it is time to attach it to the back wall of our reef tank (or wherever you want it). First, try the desired position. The plate has to be attached so that the side with the holes in them is horizontal.

Once you are convinced you have the correct position, you’ll have to support the plate so it stands upright. Use a rock, a piece of cardboard or a small box to support the acrylic plate. Once it is secure, you take the plate out of the reef tank. Leave the support system in place.

Make sure that both the plate and the glass back plate of the reef tank is completely dust-free and clean. Apply the back of acrylic plate (the part which has no holes) with the aquarium-safe silicone. Press the plate to the glass in the desired and tested position. Apply pressure for a moment so that it is secure.

Let it dry completely for 48 hours. Laat het geheel drogen voor 48 uur.

4 – Shaping your scape

Now that the acrylic plate is securely attached to the aquarium, it is time to shape our floating reef. Glue a few smaller rocks to the base plate around the holes. Use silicone. After this, they have to cure for another 24 hours.

After that day, you can attach more rocks to your base plate. Be sure you create a small cave around the drilled holes. Animals will use it for shelter. When making the scape, it is important to keep in mind where you will place all the corals. This ensures that there won’t be wasted space because of not thinking through the construction. When gluing these rocks, we do not use silicone but the typical rock glue for aquascaping use.

5 – Cherry on the pie

After a bit more of curing, all the rocks are securely attached. The supportive construction may be removed. The scape now rests completely on the base plate and the back of the aquarium. Now it is finally time to fill the reef tank.

In a few weeks, the first corals may be added.

Follow the reef tanks of Dave Notter on Instagram.