Methods of reinforcing terrace walls.
• 1). To create relief and prevent substrate movement, the terrace can be carefully laid out with stones, usually of a dark color. The stones should be flat and of the right size so that, when stacked in a chain, they form the edge of the terrace. The stones should not be very large; their function is to lie firmly on the bottom and prevent sand from sliding. Since sand grains seep through uneven joints, it is safest to put a film inside the terrace.
In this case, the stones will serve merely as decoration hiding the polyethylene. If necessary, they can be glued in several places with drops of silicone adhesive. Heavy objects should not be placed directly on the glass bottom or substrate; it is advisable to place Plexiglas plates or another material under them. It is quite possible that you can adapt a suitable driftwood piece as the terrace edge.
Remember that in any case, the ledge should look like a natural formation; it is undesirable for glue joints, film, or other structural elements to be noticeable. In aquariums with substrate-digging fish, large stones serving as the base for high terraces are placed directly on the bottom, and in some cases fastened with epoxy resin or cement. If the terrace edge is created from artificial materials, such as plastics or ceramics, the outer surface must be carefully matched in texture and color to natural materials.
From various types of slate – anthracite, gray, or light brown – you can build not only terrace ledges, but also various structures with shelters and caves in front of the back wall of the aquarium. Naturally, all of this must be thoroughly washed before installation, and driftwood must be treated as well. After that, we pour in the pre-prepared substrate.
• 2). Terrace steps are reinforced against shifting using glass strips or Plexiglas plates bent to the terrace profile at various heights, inserted into the substrate. A strip of the required length and width is cut from plexiglass (if it is placed transversely or at an angle, with a bevel toward the front glass) and bent according to a given template. It is bent over a gas burner flame. Plexiglas, heated over fire, easily bends and takes the desired shape. The glass is installed on the bottom and the substrate is poured in.
To prevent the bent plexiglass strips from shifting during substrate cleaning, a plexiglass strip should be glued perpendicularly to the lower part, placed on the glass bottom, and covered with substrate and stones on top. After laying the substrate, the plexiglass can be masked with stones. You can coat it with silicone aquarium glue and sprinkle it with small pebbles, or glue flat pebbles along the top edge.
• 3). A terrace box of a suitable size can be glued from rigid PVC plates using Tangit (cold welding). Thus, the fish will not be able to level the upper tier of the terrace with the lower one. The box is shown in cross-section in the figure. The front plate can be covered on the outside with gravel (using silicone rubber as glue), and the top edge of the terrace box can be decorated with a cut piece of root wood. The boxes should not be too large! They are easier to handle (specifically, to remove) when they are small.
• 4). Mopani driftwood is suitable for a terrace in an aquarium. You can create a very beautiful, natural corner terrace in your aquarium that will not slide down. The driftwood is heavy, has spent a long time in water, sinks, and does not require any additional processing.
• 5). Or a ceramic structure might work. Ready-made pots, grottoes, imitations of all kinds of hollow driftwood, stumps, backgrounds, etc., are available commercially. Fired clay is a good material, 
quite durable, neutral, and easy on the eyes. In certain cases, plants have to be planted in porous ceramic pots made of fired clay. The pots can be clay or plastic. Their bottom should have several holes, usually at least 4-5. In addition, it is advisable to make holes in the side walls near the bottom. The substrate is placed in the pots in three layers. Medium-sized pebbles are poured onto the bottom, followed by a layer of substrate into which the plants are planted. This can be a mixture of coarse sand with clay and peat, depending on the plant’s needs. After planting, the substrate is covered on top with coarse sand and pebbles.
• 6). You can use plastic plaster mesh, 3 and 5 mm; you can make backgrounds, sausages, and small terraces on driftwood out of it, tie any plant to it, weave in substrate, hang it between branches, and grow something on it. You need to take the mesh, cut out two pieces of the required shape, put substrate between them, and sew along the perimeter with fishing line – and there you go, the mound is ready, you can grow moss, *Hemianthus callitrichoides* (cuba), or something else on it, and the main thing is that it’s convenient to trim later: pull it out and trim it, especially moss, so it doesn’t spread all over the aquarium.
• 7). You can place the substrate into a synthetic mesh with sufficiently large mesh size so that pebbles do not spill out, make cross-shaped cuts on top for planting plants, and lay such a sausage between the strips fencing off the terraces.
• 8). You can use glued cuvettes made of transparent plexiglass in the aquarium, which are barely noticeable in water. Such cuvettes can be rearranged in the aquarium however you like. You can place substrates of very different compositions in them: from simple sand to complex mixtures with complex fertilizers. The use of flat cuvettes makes substrate cleaning easier: they do not need to be removed from the aquarium. It is entirely possible to keep plants requiring different substrate compositions in a single aquarium.
• 9). Different plants have different light requirements, which necessitates grouping them at different levels and equipping hanging terraces, which are most often made of plexiglass.
Aquarium terrace made from improvised materials.
We draw the layout of the terraces (or terrace) in the aquarium on a piece of paper, and only when you are firmly convinced that everything is to your liking can you begin the actual manufacturing. The most important advantage of a terrace made of polyurethane foam is the weight of the structure.
To make the terraces we will need: thick cardboard; glue or adhesive tape (scotch tape); polyurethane foam; scissors, a brush; cement (grade does not matter); fine pebbles (for decoration). First, we cut a rectangle the size of the aquarium bottom from oilcloth and draw the terrace contour on it. We cut a strip of cardboard the height of the planned terrace (10 cm) and glue it along the drawn contour. As a result, we should get a so-called terrace mockup.
Then we take a can of polyurethane foam and “blow” it onto the glued cardboard. Along the strips or across – it doesn’t matter, everything depends on your desire. Attention! After drying, the foam increases in volume by 3-5 times (depending on the foam manufacturer). Usually, everything is indicated on the foam can labeling.
Although at first glance it seems that the foam dries quite quickly, it is better to wait the time indicated on the can until it is completely dry. Now we begin the next, probably the most labor-intensive stage of creating terraces. We need to remove all excess foam. Armed with a knife, we remove the foam from the inside of the structure, having previously removed the cardboard which is no longer needed. Why from the inside?
The fact is that the front side of the foam has sagging areas, pits, and depressions, which provides a large field for design thought. Attention! When removing excess foam from the terrace, be sure to leave the “bottom” (the part of the foam it stood on) for better stability and substrate filling. Remove as much foam from the walls as possible. The thinner the remaining layer, the better. You can make something like caves or breaches in the future terrace.
After finishing with the foam, we proceed to the next stage. Now we will cover the foam with cement. We prepare a cement mortar with the consistency of thick sour cream. We take a brush and begin covering the structure with the prepared mixture from all sides. After drying, we apply a second layer, then a third… The thickness of the cement layer on the foam must be at least 0.5 cm.
When applying the final layer of cement, you can immediately sprinkle it with sand or fine pebbles to give a natural look. After that, everything is simple: we install the terrace in the aquarium. If you covered the foam with too thin a layer of cement, the terrace will float and soak with water. In this case, we place large stones on its “side bottom extensions” or simply cover them with substrate.
Aquarium substrate care. What to do if the aquarium is heavily neglected?
Creating decorative terraces for substrate in an aquarium. Design principles. 
Last changes and additions made on January 21, 2013.
