Decorated Polystyrene Resin for Aquariums

The most beautiful of aquarium decorations is undoubtedly the one that gives the most impression of observing a biotope environment closest to its natural state. For this, we strive to conceal all electrical equipment behind plants, stones or other roots.

What is to be viewed from the bottom of the water through which one sees the plaster of the wall is different from time to time. Of course, there are the posters representing a background nature, but we do not really let ourselves be taken serious, although the latter still arranges quite a lot the aesthetic appearance.

On the other hand, we all dreamed of admiring fabulous resin decorations, telling us that their price was inaccessible and that their manufacture remained very tedious. Well no. On the contrary, it is very simple. The only problem is that it takes time and needs to be rigorous. But I assure you that this little work is worth the effort to invest, because the result is really up to the task.

As for the cost, the manufacture of the decor of my 200 liter tank on two of its sides has returned to me less than 30 €.

aquasquale resin


Equipment to be used:

– Extruded polystyrene (this is the one used for insulation).
– Epoxy resin … Personally, I use the R123 from Soloplast supplied with its hardener.
– Gloves (because the resin burns the fingers).
– Various dyes, foodstuffs or not.
– Sand of different granulometries (the sand of construction site is very suitable).
– Brushes cheap, because these will be unusable after use.
– Various cutting tools: cutters; Knives of different sizes, with and without teeth; limes …
– A thermal stripper, very practical for finishes, but not mandatory.
– Aquarophilic silicone.

The realization of the system:

First, measure the inside of the aquarium that will be destined to receive the decoration. If the tank has an internal decantation as was my case, it is the ideal opportunity for it to be hidden. I had opted to move it and make another PMMA that would have a shape more suited to the tank, and that would blend perfectly into the decor.

Before attacking, we must ask ourselves the question of the biotope that we want to achieve. It will be necessary to choose the thickness of the polystyrene according to this. A thickness of 4 cm is sufficient for a planted trough. On the other hand, a thickness of 10 cm may be better suited to an African cichlid or reef tank.

Once these different measures have been taken, all that remains is to cut the polystyrene block to the size of the aquarium, taking care to remove 1 cm on each length so that the block can then keep play when it is inserted In the tank.

The shaping of the decoration will begin now, with the sculpture of polystyrene. This phase is the longest and most tedious of the realization. Thus, before attacking, one must determine the form that the decoration must have. A rocky decoration will be different from a shore of earth … The sculpture must respect natural forms; For this, it is better to draw the different cuts to be made with a marker, so as to have an aproximative idea of ​​the final result. To sculpt, any sharp object will be useful, and one must not be afraid to carve in depth so that the tortuous aspect is really highlighted.

Once this work has been completed, it is necessary to pass a slight stroke of the thermal stripper, so as to tighten the polystyrene balls and form a hard crust. It is necessary to take care with softness not to dig too much the polystyrene which melts very quickly under the effect of the heat.

The next step is to coat all sides of the epoxy resin decor. Polystyrene tends to release toxic solvents (styrene) in contact with water. This is why it must be coated with resin, even on the faces that will be glued to the glass of the aquarium.

The resin must be mixed with dye to achieve a natural effect. Here again, the color will be determined according to the expected result. I used earth from Siena and gray to get a “shoreline” effect. In addition, the use of dye makes it possible to see where one has passed and thus to avoid any lack. All that remains is to apply the resin to the decoration. Better to make small amounts of mixture because the resin dries relatively quickly.

Then comes the time of sanding. It is aesthetically interesting to use sand of various granulometries: this gives a more natural effect. For my part, I used construction sand.