• HDPE Full-Wall Ponds

    • PE is our sealing material of choice. The advantage is both durability and indestructibility. In addition, PE full-wall ponds can be expanded at any time and the fact that the panels, which are up to 1/2″ thick, are welded together creating a homogeneous material, just as if the pond had been cast in one piece. In addition, the outer walls can be used as form work if you want to fill the work area with concrete. Furthermore, PE full-coat ponds have a very smooth surface so that the Koi cannot injure themselves. The processing speed is also gigantic, so that even ponds with 15,000 gallons or more can be built within a few days.

    • Foil Ponds

    • There is one compelling argument in favor of foil ponds: the price. Depending on the quality of the foil used, the costs for a foil pond can be significantly lower than those of other seals. But be careful: foils vary significantly in quality. It is also advisable to have the foil pre-cut to the existing pond shape by a specialist so that no wrinkles form on the floor. EPDM foils are a little more expensive but are recommended due to their elasticity. Probably well over half of all ponds are still made as foil ponds.

    • GRP Ponds

    • Glass fiber reinforced plastic is abbreviated to GRP. This material is made on site from glass fiber mats and polyester resin and, if processed correctly, is practically indestructible like PE full-coat ponds. The advantage of GRP is that it can be adapted to practically any surface, or in other words: the surface of the GRP reflects the substructure. But this is also a small disadvantage: before the GRP is installed, a stable pond shell must be built onto which the GRP is applied. You should also pay attention to the surface quality, which can be dangerously rough if processed poorly, which poses a risk of injury to the Koi. GRP is also one of the more expensive seals.

    • Polyure

    • Like GRP,  Polyure is a sealing option that is applied to a finished surface and practically reproduces it. Polyure can only be processed by specialist companies. However, if the substructure is stable and the processing is correct, these ponds are also among the most durable. Like GRP and PE full-coat ponds, sealing with this material is one of the more expensive and professional ways to seal a pond against water leakage.
    • In addition to the four options mentioned above, there are certainly a few others that we have not listed here due to their low relevance. Well over 90 percent of all ponds are created using one of the four sealing methods mentioned.

Step 3 – To Build and Plan your Koi Pond: The Size !!!

Everyone dreams of a large pond. But many owners of large ponds today would like a smaller one. Water, water, water, water… that’s what everyone thinks when they think about building their first pond. The more the better. But many Koi pond owners with one of these mega ponds of 25,000 gallons or more would be happier if they had a smaller and more manageable pond. Why? Giant ponds are expensive to maintain and difficult to manage. A simple example: In a 5,000 gallon pond, you can change 10% of the water within an hour, using a standard domestic connection. In 25,000 gallon pond, this takes five hours. To circulate a 5,000 gallon pond once an hour, you need around 300 watts , but at least 1,300 watts in a 25,000 gallon pond. We certainly don’t want to speak against large ponds here. We would just like to remind you that the pond construction itself is the cheapest part of the Koi pond event. The running costs are what end up being expensive. In our experience, Koi ponds with a volume of between 3,000 and 6,000 gallons are ideal. But there is one more thing you need to know: it is not the size of the pond that determines the well-being of the Koi, but the water quality.

Step 4 – To Build and Plan your Koi Pond: The Form !!!

There is a simple rule for the shape of a koi pond: the simpler the better. The simpler the shape, the easier it is for the water to flow through it and the more effectively the dirt is transported from the pond to the filter. In addition, the flow in ponds with a simple shape is stronger with the same pump output than in ponds with a more complicated shape. So what is a simple shape and what is a complicated shape? A circular pond would be perfect, regarding transportation of the fish waste towards the bottom drain. You can also opt for a rectangular shape, rectangles with rounded sides, kidney shapes, 8-shapes or, in other words, a shape that has as few bulges in or out of the pond as possible to disrupt the flow. When choosing the shape, also make sure that you can still catch the Koi later. Landing net handles are available up to a maximum of 11 feet. And you wouldn’t believe how many Koi lovers today would build their ponds smaller just to be able to catch their Koi better.

Step 5 – To Build and Plan your Koi Pond: The Depth !!!

Nothing has changed the way we think about pond construction as much as the depth. If you browse through Koi literature from 10 years ago or more, you will repeatedly come across information that Koi ponds should be at least 6 feet deep. Due to the cooling in winter, depths of 6 feet and more are even recommended. Based on this information, countless ponds with depths between 6 and 10 foot were built. Today, this is no longer done. The number and value of the arguments in favor of ponds with a maximum depth of 5 feet are convincing:

    • Koi grow better in shallower ponds. Whether this is due to the lower water pressure or some other reason has not been researched. However, growth results are much better in shallower ponds than in deep ones.
    •  Koi are more vital in shallower ponds.
    •  Koi suffer less from physical weaknesses and if a Koi suffers from physical weaknesses, it recovers much more quickly in shallower ponds. Due to their smaller volume, shallower ponds have a better current than deeper ones. Incidentally, the decisive factor in ponds is not the volume but the pond surface.
    •  Koi are easier to catch in shallower ponds. If a Koi needs to be caught, it is much easier to catch in shallower ponds than in deeper ones.
    •  Koi suffer much less from tumors in shallower ponds than in deep ones. Incidentally, this knowledge comes from Southeast Asia, where very deep ponds are built for cooling purposes. There is a significantly higher number of tumors there than in countries where the ponds are shallower. But tumors are also observed in ponds that are 6 feet or deeper in this country.

Conclusion: A pond depth of 5 feet is completely sufficient, even if this comes at the expense of several cubic meters of volume and requires a little more heating in winter.

Step 6 – To Build and Plan your Koi Pond: The Current !!!

Let’s be honest: when you were planning your Koi pond, did you give enough thought to what kind of current your pond would have later on? Or did it just turn out the way it did? Because in most cases, unfortunately, that’s the way it is. The current is one of the most important points when it comes to transporting dirt from the pond to the filter and where the skimmers and floor drains should be placed in the pond. It is therefore advisable to first draw the pond on a piece of paper and use flow lines to mark in which direction and where the current will build up later. This may be easy in simple shapes. However, if you have a more complicated pond shape, you may well need several opposing circular currents to flow completely through the pond.

Step 7 – To Build and Plan your Koi Pond: The Circulation Speed !!!

The circulation speed at which the water is exchanged between the pond and the filter has a much greater influence than is often assumed. The circulation speed is basically nothing other than the effective pump output in relation to the pond size. In other words, how often the pump manages to exchange the pond via the filter. And the faster the circulation speed, the more effectively dirt particles are transported from the pond to the filter, the stronger the current is, the faster the ammonium that accumulates in the pond is transported to the biological filter and the better the biological filter works. It’s that simple. And if you really want to take the Koi hobby seriously, then you would be well advised to aim for a circulation speed of around 1x per hour. Only with very large ponds of 25,000 gallons and more can you gradually deviate from this rule and exchange the water more slowly. For very small ponds of 2,500 gallons or less, an even faster exchange rate than 1x per hour is recommended. You may now be wondering why the circulation speed is determined in this planning step and not later when determining the pump output. The reason for this is simple: the circulation speed is ultimately used to calculate the number of floor drains, skimmers and return lines required.

Step 8 – To Build and Plan your Koi Pond: Amount of Bottom Drains and Skimmers !!!

If the pond is to function as desired later, the right number of floor drains and skimmers is an important factor. Floor drains and skimmers are the pipes through which the water and dirt are transported from the pond to the filter. Regarding the flow rate in these pipes, the following applies: If the water flows too quickly, the dirt in the pipes is transported away to the filter very well, but on the other hand the difference in level between the pond and the first filter chamber becomes correspondingly large, which is a disadvantage. On the other hand, if the water flows too slowly in the pipes, the difference in level between the pond and the first filter chamber is small, but some of the dirt will settle in the pipes instead of being transported to the filter. This issue therefore requires a middle ground. And this can be found at around 2,500 gallons per hour with a 4″ pipe. With the skimmer, 2,000 gallons per hour is sufficient. If you have a circulation rate of once per hour and the pond has 7,000 gallons, two floor drains and a skimmer are recommended. If you choose one more floor drain, the flow rate will decrease; if you choose one less, it will increase. The fact that floor drains and skimmers are always made in 4″ is explained on the one hand by the removal of dirt and on the other hand by the reduction of friction losses, which would increase exponentially with smaller pipes. For very small ponds of 2,500 gallons and less, choosing the right number of floor drains and skimmers becomes more difficult. With a circulation rate of once per hour, the calculation would result in the use of only one pipe. However, this would not be optimal in terms of flow. Everyone has to decide for themselves whether to use one or the other additional pipe as a reserve. Experience has shown that many Koi lovers later want to expand their pond or filter. In this case, reserve pipes can be helpful.

Step 9 – To Build and Plan your Koi Pond: Amount and Size of Return Pipes !!!

In step 8 we talked about the number of floor drains and skimmers. Now we talk about the right number of return lines. We showed that the flow rate in floor drains should neither be too high or too low. And in principle the same applies to the return lines from the pond to the filter. If the flow rate is too low there, there will be no flow in the pond. If, on the other hand, it is too high, the pipe friction resistance generated by the high flow rate will ensure that the pump loses power accordingly. That’s the theory. However, since the flow in the pond is a key factor for a functioning pond, the water should be returned to the pond at around 1 – 1.5 yard/second . As a rough estimate, you can achieve 1 yard/second, which means that if you return 2,500 gallons per hour to the pond via a 2.5″ pipe, the flow rate in a 2″ pipe at 2,500 gallons per hour is 1.5 yard/second. Since the floor drain pipes and skimmer pipes are also designed for 2,500 gallons per hour, it is recommended to choose the same number of return pipes as you have on the floor drains and skimmers. The only difference is that you then choose a 2″ or 2.5″ pipe. If you choose 2″, the pump performance will decrease and the flow will be stronger; if you choose 2.5″, the flow will tend to decrease and the pump performance will increase slightly.

Step 10 – To Build and Plan your Koi Pond: Exit Height of the Return Lines !!!

Even something as seemingly banal as the height of the return pipes in the pond should be considered in advance. If you just look at it simply, you could say that the return pipes that return the filtered water to the pond should ideally arrive as high up in the pond as possible. Let’s say that the top edge of the pipe is perhaps covered by 2 inches. After all, you want to feed the ‘fresh’ water into the pond as high up as possible to ensure that the water to be filtered always flows off the bottom of the pond via the floor drains. That is basically correct. However, this consideration forgets winter. Because, especially in uncovered ponds, you want the water surface to be as calm as possible in winter. And this can only be guaranteed if the water is not fed in so high up, but at a depth of around 8″ below the water surface. In order to accommodate both scenarios, we always let our return pipes enter the pond about 8″ – 16″ below the water surface and provide them with a 90° angle that can be used to adjust the flow direction. In summer, we recommend that our customers have this pointing upwards and in winter either horizontally or slightly downwards.