Pond construction

GFK works: Construction of a koi pond / garden pond

Garden ponds and koi ponds made of GFK are certainly the Mercedes among the ponds.

We show you here a picture gallery and video`s of the construction of a GFK pond which was originally planned and built as a concrete pond, but the pond had considerable defects. The Koi pond was very strongly leaky, despite several attempts on the part of the pond farmer (horticulturist) the pond did not become watertight.

The Fischgut received the order to permanently rehabilitate the pond without damaging the beloved Koi.


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First of all, a temporary pool had to be built, for this purpose it is best to use a stable pool. The pool had a water volume of approximately 12 m3, which is enough to keep even bigger Koi harmless for one or two weeks.

For safety reasons, the pool was equipped with two smaller garden pond filters and a ventilation system, the garden pond filters were run in three weeks before the construction measure.

It should also be noted that the pool is filled with the pond water, so that the fish are transferred into their usual water.

 (Tap water is very cold, temperature shock in summer. It is also important that the Koi do not experience any change in water parameters, stress, mucous membrane, etc.).

First the old water lily was salvaged and parked in the pool, then the Koi came to their new home.

After moving the Koi, the pool should immediately be covered with a stable net, as the Koi like to jump after moving them.

First of all, the pond must be thoroughly cleaned (with powerful steam jets) so that the pond can dry well, but this can take several days in good weather.

It is important to catch a stable warm dry summer time, in this case we had a 35C° bevel. This was good for the pond, but you have to work very fast and never mix too much resin with hardener.

After three days the pond was dust-dry and we could start with the preliminary work.

Pipes had to be sealed, corners and edges had to be sanded down, the pond had to be thoroughly vacuumed so that it could be primed.

The primer already closes all porous areas / crevices / cracks. Depending on the substrate, the primer must be applied twice. This should all be possible in one day.

Once the pond has been properly primed, you can start laminating (which you should always do in pairs).

We could only work with approx. 1m long pieces of fleece (torn), because it was simply too hot, in the wet-wet procedure. Once the pond is completely laminated, it has to be roughly sanded to laminate the second layer. As the substrate was very stable (concrete/stones), two layers were sufficient. The duration, only for the pond laminating, was two days. Only the upper loose quarry stone edge got a third layer for stability reasons.

The pond must now be thoroughly sanded, as the processing and the fast drying fleece and resin can produce very sharp spikes.

Once the pond has been sanded and thoroughly vacuumed, the TOP COAT can be applied in the colour green – here, the exact addition of hardener must also be observed. (too fast or too slow or no hardening at all)

This work should be done by at least two men in 4 max. 5 days with a pond size of approx. 50m3.

After the TOP COAD has dried thoroughly, the water from the pool can be pumped back into the empty garden pond. The first thing we did was to put the water lily back into the new pond. Only when most of the pool water (former garden pond water) had been pumped back into the pond, could the Koi return to their new/old homes.

The pond was only a quarter full, but by its construction we could start the pond filter, here a module filter 4 years old BLUE EDITION with TWIN plant (to buy under www.fischlando.de ) directly.

Only this way we had enough time to fill the pond very slowly with tap water over several days.


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