Do you have a question? No doubt we have an answer for you!

Below you will find an overview of frequently asked questions in the field of (swimming) ponds and biopools and about the products of AquaForte.

Pond and Swimming pond in general

My pond is green. How do I clear my pond?

A green pond is caused by algae. There are two types of algae: filamentous algae and floating algae. Floating algae give a green glow to the pond water, making the water not clear anymore. This can be fought with the help of a UV-C unit, which is therefore indispensable in every pond. How does UV-C work? The pond pump pumps the pond water through the UV-C unit, where it comes into contact with UV-C radiation. This radiation affects the DNA structure of single-cell microorganisms in the pond such as bacteria, viruses and algae. They can no longer multiply, die and disappear from the water. The result is a clear and healthy pond without the addition of chemicals.

Filamentous algae can be combated with different products, such as AquaForte Oxypond, a filamentous algae brush or the AquaForte Phospat. Phosphate is one of the main causes of (filamentous) algae in the water. AquaForte therefore offers various solutions to remove the phosphate, such as the Phospat cartridge and the liquid Phosfree. These products make it possible to keep the phosphate value below 0.035 mg/l. This is the ‘magic’ limit that ensures that algae no longer grow, without disturbing plants and bacteria.

How do I prevent my pond from becoming cloudy?

A cloudy pond can be prevented by choosing the right filter system. There are several ways to filter pond water. With mechanical filtration the coarser, floating waste is filtered out of the water. With biological filtration, beneficial bacteria convert the waste from the pond into harmless substances. AquaForte has a wide range of various filter systems to ensure a clean and healthy pond. In addition, we recommend to filter your water with a UV-C lamp, to prevent green water caused by algae. Translated with www.DeepL.com/Translator (free version)

What are the optimal water values for my pond?

All the water values combined determine the overall water quality. Since ponds in a garden
are often much more densely populated than they are in the wild, we need to give nature a
helping hand to achieve a healthy balance.

The following values are the most important ones for a pond:

  • pH: 6,5 – 8,5
  • KH: 6 – 10° dH
  • GH: 8 – 12° dH
  • Ammonium: 0 mg/l
  • Nitrite: 0 mg/l
  • Nitrate: <30 mg/l
  • Phosphate: <0,03 mg/l

Acidity (pH): 6,5 – 8,5
This value affects the wellbeing of your plants and fish. The value must be between 6,5 and 8,5.

Acidity (pH): 6.5 – 8.5
This value affects the well-being of your plants and fish. The value must be between 6.5 and 8.5.

Carbonate hardness (KH): 6 -10° dH.
Carbonate hardness (KH) is also called temporary hardness. KH serves as a buffer of the pH; the KH stabilizes the pH as it were. Nitrifying bacteria consume KH when converting ammonia into nitrite and nitrate (1 part ammonia costs 7 parts KH). When the KH drops below 3° dH, the nitrification process stops.

Total/joint hardness (GH): 8-12° dH
The combined hardness of the water is determined by calcium and magnesium. For the growth of aquatic plants it is very important that the GH is not lower than 8° dH.

Ammonia/Ammonium: 0 mg/l
The secretion of fish and the decomposition of organic substances cause ammonium to enter the pond water. If the pH value is too high, ammonium is converted into ammonia, which is toxic and causes health problems in pond life. This value should therefore be 0. Ammonia is already harmful at 0,1 mg/l. Bacteria convert ammonium into nitrite.

Nitrite: 0 mg/l
Nitrite is formed during the decomposition of ammonium. Nitrite is less toxic than ammonium, but can also cause health problems in the pond. The nitrite value in the pond should therefore also be 0. Bacteria convert nitrite into nitrate.

Nitrate: < 30 mg/l
Nitrate is not poisonous, but is seen as an undesirable substance in the pond. Up to 100 mg/l it is harmless, but it is a food source for algae and inhibits the growth of small fish. In addition, it increases stress in the fish. Bacteria convert nitrate into nitrogen gas (N2).

Phosphate: < 0.03 mg/l.
For fish ponds it is less important, as floating algae are treated with UV-C and filamentous algae are often controlled with agents. For ornamental ponds/swimming ponds the phosphate content is preferably lower than 0.03 mg/l to control algae growth.

When is it extra important to pay attention to the water values of the pond?

  • At the startup of the pond
  • During filling the pond with (tap) water.
  • At a large fish stock
  • For a lot of organic waste
  • When the pond water is not in balance

Why are more and more people opting for a swimming pond?

More and more people choose to swim in pure water, without chlorine or other chemicals. In addition, a swimming pond often has a nicer appearance than a swimming pool. A swimming pond has the appearance of a (tight) pond, but you can swim in it.

Products for (swimming) ponds and biopools

Why does a (swimming) pond need a filter installation?

Almost all ponds need a filter installation, especially if it is used intensively. A pond without a filter is only possible if there are many purifying plants present, no or hardly any fish in swimming and the pond is not in the sun. Especially if you have a pond with fish or a pond with a lot of swimming, it is important that the water is properly filtered. If waste products are not sufficiently removed from the water, a cloudy pond with unhealthy water will be created.

What should I pay attention to when choosing a filter system?

When choosing a filter system, four factors play a role:

  • The size of the pond; larger ponds need a larger filter.
  • The number of fish in the pond; the more fish in the pond, the bigger the filter should be.
  • The number of purifying plants in the pond; plants relieve the filter by taking care of part of the water purification.
  • The position of the pond; if a pond is fully sunbathing, the chance of algae formation is higher.

Why doesn’t a sand filter work on a swimming pond?

To say that a sand filter does not work on a swimming pond goes too far. But when a sand filter is installed, it costs an enormous amount of maintenance and energy (costs). A sand filter is not good against biological swimming water. Practice shows that a sand filter is usually sealed within 3 weeks from the inside and the sand turns into a lake like a block of cement in the sand filter. This is because the biofilm from the natural swimming pond in combination with lime causes all the stagnant sand to stick together. As a result, the filter can no longer be rinsed and hardly any water can be pumped through it.

What’s the difference between a sand filter and a Beadfilter?

At first glance, sand filters and Beadfilter do not differ much from each other. Both are closed pressure vessels containing the filter medium. In sand filters (of course) sand or glass (AFM) is chosen as the filter medium. Beadfilters have the so-called “Beads” as filter medium. These are millions of plastic grains that float within the filter. This is an immediate difference; sand lies at the bottom of the filter. The most important difference between a sand filter and a Beadfilter is in the operation of the filter media. Sand or glass provides mechanical filtration. Beads provide mechanical and biological filtration. In fact, the biological filtration character of the Beads also ensures biological balance in the pond water. Ideal for a swimming pond.

What is the difference between mechanical and biological filtration?

Mechanical filtration is used to filter the coarser, floating waste out of the water. In biological filtration, beneficial bacteria convert the waste from the pond into harmless substances.

What is the use of a pre-filter?

Pre-filters remove coarse dirt particles from the pond water before the water reaches the main filter. Because it is already ‘pre-filtered’, the main filter can do its job better and requires less cleaning. AquaForte has various pre-filters in its range, such as screen bend filters and drum filters.

Why is UV-C so important in a (swimming) pond?

UV-C equipment offers the solution against green pond water and is therefore indispensable in every (swimming) pond. UV-C is an environmentally friendly technology that ensures rapid improvement of water quality and clear water without the addition of chemicals. UV-C also protects the fish against germs.

How does UV-C work?

The pond pump pumps the pond water through the UV-C unit, where it comes into contact with UV-C radiation. This radiation affects the DNA structure of single-cell microorganisms in the (swimming) pond, such as bacteria, viruses and algae. They can no longer multiply and disappear from the pond. The result is a clear and healthy (swimming) pond.

How often should I replace my UV-C lamp?

UV-C lamps have an average life span of 9000 operating hours. After that, the UV-C lamp still works, but the radiation is less powerful so that the desired effect is not achieved. Therefore, it is important to replace the UV-C lamp every year for optimal performance. Amalgam lamps have a longer life, namely an average of 12,000 hours.

How do I maintain my UV-C lamp?

The UV-C lamp is in a quartz glass. If deposits are formed on the glass (e.g. due to lime or algae), the effect of the UV-C lamp decreases. The UV-C radiation can then reach the flowing pond water less well. It is therefore important to keep this quartz glass clean with a suitable agent. Always use a soft cloth to clean the glass, this prevents scratches.

What does a pond pump do?

A pond pump pumps the (polluted) pond water to the mechanical and biological (pre)filter and the UV-C filter. In addition, a pond pump ensures water circulation in the pond, allowing the water to better absorb oxygen, and a pump easily creates a fountain, stream or waterfall.

What should I pay attention to when choosing a pond pump?

The choice of a suitable pond pump depends on four variables:

  • Dry or wet setup:In a dry setup the pond pump is outside the pond. The advantage of a dry setup is that the pond pump is free and easy to maintain. With a wet setup the pond pump is in the pond or in a filter under water level. The advantage of this is that the pump is neatly concealed and the hoses are less visible.
  • Pump head: This is the maximum number of meters a pump can pump. Pay close attention to the loss in head that the piping and for example filters, UV-C units and heating entails.
  • Capacity (liters per hour): the capacity of a pump indicates how many liters of pond water a pump can handle per hour. This capacity depends on the head that the pump has to bridge. A common rule of thumb is that a pond pump should pump 25 to 50% of the pond water per hour.
  • Energy consumption:The lower the wattage, the lower the electricity bill. Because a pond pump is continuously on during the hot months, it is advisable to choose an energy-efficient pump. Different pond pumps give you the possibility to determine your own energy consumption and capacity.

Why should I heat my pond?

In winter your pond can freeze. This makes your fish more susceptible to diseases. You can therefore choose to heat your pond using a heat pump. A heat pump ensures a completely ice-free pond and a better temperature for the fish. In addition, there are a number of advantages:

  • It prevents the risk of frost damage.
  • Fishes come through the winter healthy and have more resistance after the winter.
  • The filter remains more active at warmer temperatures
  • .

  • The pond water is more quickly balanced in the spring.

What causes oxygen deficiency in my pond?

Oxygen is essential for all living organisms in your pond. It is important to maintain your oxygen level to prevent fish mortality and algae growth. Oxygen deficiency can be caused by :

  • A rising water temperature in spring and summer
  • Binding organic material at the bottom of your pond, such as leaves and uneaten food.
  • Plants and algae absorb oxygen from the water at night, to gradually give it back during the day. In the morning there is therefore less oxygen
  • .

How do I know if my pond lacks oxygen?

Often this can be seen quickly because fish move slowly through the water, gasping for air or displacing each other at the most oxygen-rich spot. At that moment there is a shortage of oxygen and we recommend aeration of your pond directly. This can be done by moving the water surface as much as possible with for example an air pump, fountain, waterfall or even a garden hose.

What is the added value of a skimmer in a pond?

Due to changing weather conditions, waste such as leaves, pollen and dead insects are regularly blown into the pond. Skimmers catch this debris so that the water surface remains clean. They prevent dirt from sinking to the bottom, where it rots further and poses a danger to the oxygen content of the pond.

How does a sieve filter work?

In a sieve filter the water from the pond is led over a curved sieve. The sieve consists of hundreds of triangular rods with a spacing of 0.2 or 0.3 mm (also called 200 or 300 microns). The sticks are slightly tilted, so that the coarser dirt remains on the sieve and the ‘sieved’ water falls through it. The sieved water is led further to the main filter. AquaForte has various sieve filters in its range, such as the UltraSieve, MidiSieve and CompactSieve.

How does a drum filter work?

Drum filters are fully automatic pre-filters. The water enters the drum filter through the inlet chamber, after which it ends up in a drum-shaped sieve. The drum is equipped with a filter mesh of, for example, 60 micron, which means that dirt particles larger than 0.06 mm cannot pass through the mesh. These dirt particles stick to the inside of the drum, so less and less water can flow through the drum. This causes a difference in water level inside and outside the drum. The float switch detects this difference in water level, so the controller starts the rinsing process. The device therefore determines itself based on the contamination when the nozzles rinse the sieve clean. The dirt is flushed into the drain chute. You can choose whether the nozzles rinse with tap water (minimum pressure 1 bar) or clean pond water. The filtered water flows through the sieve and is then directed to the main filter.

What are bead filters and how do they work?

A bead filter is a main filter, which is widely used in swimming ponds, koi ponds and larger ornamental ponds. Bead filters are closed (pressure) vessels, filled with thousands of plastic beads. These beads are very close together and form a layer through which the water is pressed under pressure of a pump. The dirt particles remain stuck in the beads. If the filters are used for a longer period of time, the biofilm (the sticky layer) around the beads becomes thicker, which causes increasingly fine dirt to be collected. Besides mechanical filtration, biological filtration also takes place in a bead filter. Useful bacteria attach themselves to the beads and break down harmful substances such as ammonium, nitrite and nitrate. A bead filter is easy to operate manually via a six-way valve. With this six-way valve various functions can be set, such as cleaning a filter. AquaForte has various bead filters in its range, such as the UltraBead and EB series.

When do I use a pressure filter?

Pressure filters are suitable for the smaller garden ponds with a small fish stock. Nowadays, pressure filters are often equipped as standard with a built-in UV-C lamp, which prevents the water from turning green, and a backwash function for easy maintenance.

What is the advantage of a variable pump?

With a variable pond pump you can control the flow, and thus the power consumption, of a pump. The advantage is that a pump is much more energy efficient than other pumps, which run continuously at the same position. The pumps are not only advantageous for your energy bill, but they also contribute to CO₂ reduction which is good for the environment.

What should you take into account when adding bacteria to your pond?

When using different pond bacteria, it is wise to let the pond rest for a few days before adding another type of bacteria to the pond. We also recommend to turn off the UV-C unit.

What is the advantage of an automatic feeder?

A feed dispenser is an easy tool to feed your fish during busy or vacation periods. In addition, you can adjust the dosage exactly to the eating behaviour of your fish. This stimulates the growth and health of the fish and prevents excess food residue in the pond, which puts less strain on the filter.