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

Common frequently asked questions about pond and swimming pond

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

A green pond is caused by algae. There are two types of algae: thread algae and floating algae. Floating algae give a green glow to the pond water, making the water no longer clear. This can be combated using 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-celled micro-organisms in the pond such as bacteria, viruses and algae. They can therefore no longer multiply, die and disappear from the water. The result is a clear and healthy pond without the addition of chemicals.

Thread algae can be fought with various products such as AquaForte Oxypond, a thread algae brush or the AquaForte Phospat. Phosphate is one of the main causes of (string) algae in the water. AquaForte therefore offers various solutions to remove 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 affecting 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, suspended waste is filtered from the water. With biological filtration, beneficial bacteria convert 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 through algae.

What are the optimal water parameters for my pond?

All water values combined determine the overall water quality. Because garden ponds often contain many more fish and other living things than in nature, we need to lend a helping hand to achieve a healthy balance.

Below are the parameters and their ideal water values:

  • pH: 6.5 – 8.5
  • KH: 6° – 10° dH
  • GH: 8° – 12° dH
  • Ammonia: 0 mg/l
  • Nitrite: 0 mg/l
  • Nitrate: <30 mg/l
  • Phosphate: <0,03 mg/l

Acidity level (pH): 6,5 – 8,5
This value affects the well-being of your plants and fish. The value should 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 to 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 falls below 3° dH the nitrification process stops.

Total/common 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 matter cause ammonium to enter the pond water. With an excessively high pH value ammonium is converted into ammonia, which is toxic and causes health problems for pond life. This value should therefore be 0. Ammonia is harmful at 0.1 mg/l already. Bacteria convert ammonium into nitrite.

Nitrite: 0 mg/l
Nitrite arises from 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 toxic, but is considered 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
Less important for fish ponds, as floating algae are treated with UV-C and thread algae are often controlled with agents. For ornamental ponds/swimming ponds the phosphate level should preferably be lower than 0.03 mg/l to keep algae growth under control.

When is it especially important to pay attention to pond water values?

  • When starting up the pond
  • During the (re) filling of the pond with (tap) water
  • In a large fish stock
  • When there is a lot of organic waste
  • When the pond water is not balanced

Why are more and more people choosing a swimming pond?

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

Frequently asked questions about (swimming) ponds and biopools

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

Almost all ponds need a filter system, 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 swimming in it and the pond is not in the sun. Especially if you have a pond with fish or a swimming pond where a lot of swimming takes place, it is important that the water is filtered properly. If waste is not sufficiently removed from the water it creates a cloudy pond with unhealthy water.

What should I consider when choosing a filter system?

Four factors come into play when choosing a filter system:

  • The size of the pond; larger ponds require a larger filter.
  • The number of fish in the pond; the more fish in the pond, the larger 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 location of the pond; if a pond is in full sunlight, there is a greater chance of algae formation.

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

To say that a sand filter does not work on a swimming pond is going too far. But when a sand filter is installed, it takes 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 within 3 weeks already glued to the inside and the sand is more like a block of cement in the sand filter. This is because the biofilm from the natural swimming pond combined with lime makes all the stagnant sand stick together. The result is that the filter can no longer be flushed and hardly any water can be pumped through it.

What is the difference between a sand filter and a Bead filter?

At first glance, sand filters and Bead filters do not differ much from each other. Both are closed pressure vessels containing the filter medium. In sand filters sand or glass (AFM) is (obviously) chosen as filter medium. Bead filters have as filter medium the so-called “Beads”. These are millions of plastic beads which float within the filter. This is immediately a difference, because sand lies at the bottom of the filter. The main difference between a sand filter and a Bead filter is in the operation of the filter media. Sand or glass provides mechanical filtration. Beads provide mechanical and biological filtration. Indeed, 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?

With mechanical filtration, the coarser, suspended waste is filtered out of the water. With biological filtration, beneficial bacteria convert 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 needs less cleaning. AquaForte has several pre-filters in its range, such as sieve 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 from 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-celled micro-organisms in the (swimming) pond, such as bacteria, viruses and algae. They can therefore 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 of 9000 hours. After that, the UV-C lamp will still work, but the radiation will be less powerful so that the desired effect is not achieved. It is therefore important to replace the UV-C lamp every year for optimum operation. Amalgam lamps have a longer life span, namely an average of 12,000 hours.

How do I maintain my UV-C lamp?

The UV-C lamp is contained in a quartz glass. If deposits form on this (due to lime or algae, for example), the function of the UV-C lamp is reduced. The UV-C radiation is then less able to reach the pond water flowing past. It is therefore important to keep the quartz glass clean with an appropriate agent. Always use a soft cloth to clean the glass, this prevents scratches.

What does a pond pump do?

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

What should I consider when choosing a pond pump?

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

  • Dry or wet setup: With a dry setup, the pond pump is outside the pond. The advantage of a dry set-up is that the pond pump is free and easy to maintain. In a wet set-up the pond pump is in the pond or in a filter under water level. The advantage is that the pump is neatly concealed and the hoses are less visible.
  • Head: This is the number of meters that a pump can pump up. Please note the loss in head that the piping and, for example, filters, UV-C units and heating entail.
  • Capacity (liters per hour): The capacity of a pump indicates how many liters of pond water a pump can process per hour. This capacity depends on the head that the pump must bridge. A widely used 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 constantly on in the warm months, it is advisable to choose an energy-efficient pump. Different pond pumps give you the option of determining the energy consumption and capacity yourself.

Why should I heat my pond?

In the winter, your pond can freeze over. This makes your fish more susceptible to disease. 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 other advantages:

  • It prevents the chance of frost damage.
  • Fish 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.
  • A heat pump extends the pond season through higher water temperatures.

What causes oxygen deficiency in my pond?

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

  • Rising water temperatures in the spring and summer.
  • Decomposing organic material at the bottom of your pond, such as leaves and uneaten food.
  • Plants and algae take up oxygen from the water at night, only to gradually give it back during the day. In the morning there is therefore less oxygen.

How do I know if my pond is lacking oxygen?

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

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

Changing weather conditions regularly blow debris into the pond, such as leaves, pollen and dead insects. Skimmers capture this debris, keeping the water surface clean. They prevent debris from sinking to the bottom, where it rots further and poses a threat to the pond’s oxygen content.

How does a sieve filter work?

In a sieve filter, the water from the pond is passed over a curved sieve. The sieve consists of hundreds of triangular rods spaced 0.2 or 0.3 mm apart (also called 200 or 300 microns). The rods are slightly tilted so that the coarser dirt remains on the sieve and the “sieved” water falls through. The sieved water is further directed to the main filter. AquaForte has various sieve filters in its range, such as 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 enters a drum-shaped screen. The drum is equipped with a filter mesh of, for example, 60 microns, which means that dirt particles larger than 0.06 mm cannot pass through the mesh. These dirt particles adhere to the inside of the drum, which means that less and less water can flow through the drum. This causes a difference in water levels inside and outside the drum. The float switch detects this difference in water level, which causes the controller to start the rinsing process. So the unit itself determines, based on the dirt, when the spray heads will rinse the screen clean. The dirt is flushed into the drain. You can choose whether the spray heads 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 are widely used in swimming ponds, koi ponds and larger ornamental ponds. Bead filters are closed (pressure) vessels, filled with thousands of plastic granules, called beads. These beads are very close together and form a layer where the water under pressure from a pump is pressed through. The dirt particles remain stuck in the beads. If the filters are used for a long time, the biofilm (the sticky layer) around the grains will become thicker, so that increasingly finer dirt is captured. 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 through a six-way valve. With this six-way valve, various functions can be set, such as cleaning a filter. AquaForte has several bead filters in its range, such as the UltraBead and EB series.lters and how they work?

When do I use a pressure filter?

Pressure filters are suitable for smaller garden ponds with small fish stock. Today, pressure filters often come 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 speed 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 thus much more energy efficient than other pumps that continuously run on the same setting. 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 consider 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. In addition, we recommend that you turn off the UV-C unit.

What is the advantage of an automatic feeder?

A feed dispenser is an easy tool to supply your fish with food during busy or vacation periods. In addition, you can precisely adjust the dosage to the eating behavior of your fish. This stimulates the growth and health of the fish and prevents excess food residue in the pond, thereby reducing the burden on the filter.