Below are the most frequently asked questions from our customers listed by category.Is your question not listed? Find more information on a topic by using the search bar or ask the question on our Facebook page.
The diaphragms of the air pump become worn and need to be replaced annually for good air output and longevity. Easily order new parts online at www.vijverproducten.shop. Also check that the air hose is not pinched or flattened.
Carbonic acid equals carbon dioxide (CO2, popularly known as carbon dioxide) is very important for the growth of aquatic plants. If enough CO2 is available to aquatic plants in free form, they can grow well, converting organic compounds and releasing oxygen under the influence of light. This is the assimilation process. The CO2 content is not constant during a 24-hour period, by the way. It fluctuates under the influence of day and night (assimilation process). Underwater plants absorb CO2 and release oxygen with the help of light. The CO2 content therefore decreases as the day progresses. At night, the process is reversed; plants take in oxygen (albeit limited) and release CO2 (albeit limited). Microorganisms, the largest producers of CO2, produce both during the day and at night. This means that CO2 will accumulate at night and decrease significantly in the afternoon. By the way, this process occurs only in well-functioning water bodies, that is, when there is a growing stock of underwater plants and sufficient activity of the microorganisms. With the pH value, we can control this process. If the pH is relatively low early in the morning (pH 7-8) and relatively high in the evening (pH 8-9) then the pond environment is functioning well. The plants will grow well and the water will be clear. However, if the pH is equally high in the morning and in the evening (pH 9 or higher), there is stagnation: the submerged plants will not grow and the picture is a pond full of algae. After the growing season, the pH will drop. The growth of aquatic plants (and algae) stagnates. Thus, they no longer absorb CO2. The CO2 level in the pond will therefore slowly increase. If the GH value (see chapter GH) is high enough, the excess CO2 can bind to carbonate and the water will not acidify. The pH value will not drop below pH 7. However, if the GH value is too low, there is insufficient calcium to bind the excess CO2. The water becomes acidic and oxygen deficiency occurs. The pH value in this case drops to values below pH 6. With a simple Aqua test set, the pH value can be determined very precisely.
Gasping for air may indicate a lack of oxygen. A quick solution to oxygen problems is to change the water and purchase a strong air pump, which is especially good at moving the lower water layers. We have a wide range of (air) pumps in our assortment that provide more oxygen. In addition, provide a wide range of oxygen plants in your pond.
The rule of thumb for the number of pond fish is: 50 cm of fish length per 1000 liters of water. That’s 10 to 12 fish in a 5,000-liter pond. This number keeps the strain on the pond environment down, because with too many fish in the pond, the water becomes polluted and runs out of oxygen.
Crystal Clear does not work well if there is (too) much movement in the water, preventing binding. Too many dissolved substances in the water can also interfere with the effect. Partial water changes are a good remedy for this. For example, change 25% of the water and repeat this every 2 to 3 days (3x in total).
Against green water (floating algae), Crystal Clear is a short-term solution. The remedy binds the algae (flakes) and the water becomes clear again. However, you do not remove the cause and new algae can form again in a short time.
If your pond water is green, then there is a very good chance you are suffering from algae. First, determine what kind of algae is in the pond. If there are green particles floating in the water, then you are suffering from floating algae. A short-term solution is to use Velda Crystal Clear. Crystal Clear is an environmentally friendly product, which precipitates dirt and algae particles on the bottom and makes the water clear. The long-term solution to this problem involves a number of measures. If not already present, apply a layer of substrate. Simultaneously add Bacterial (nitrifying bacteria cultures). Apply more pond plants. Good species at this stage are floating plants, such as water gentian, frog beetle, Azolla, duckweed or water lilies. Make sure the combined water hardness (GH value) is sufficiently high. It should be at least 8 °DH. At lower values use Velda GH-Plus to raise it again. When these measures are applied, over time the environment will stabilize and the floating algae will disappear. After the water has become clear, oxygen plants can be added. Good species are waterweed, hornwort and pondweed. Another excellent way to improve the environment and thus clear the water is to install the Cross-Flow Biofill. When using this, Velda guarantees a clear pond within three months
Crystal Clear is a solution for green water (floating algae). Alglets is a solution for string and slime algae. However, you then do not remove the cause and new algae will form again in a while.
For permanent control of green water, a UV-C Filter very suitable.
Green water means there is floating algae in the pond. You may have a filter and UV-C lamp that cannot handle the amount of water. Keep approximately the following: an 18 watt UV-C filter is recommended to keep a pond up to 9000 liters clear. Tip: If you also have fish in the pond; never overfeed. Make sure the fish eat the scattered food within a few minutes. This is because food that is not eaten is a food source for algae.
Chances are, fish predation by a heron or a cat is still occurring, even though a “deterrent device” has been installed.
Herons are smart animals and unfortunately do not always let an artificial heron deter them. As decoration, however, you can leave it in place. Much more effective is to use, for example, the Pond Protector Pond Protector, a harmless scare wire that the heron runs into with his paws. When touched, it triggers a startle reaction, causing herons but also cats to prefer to avoid the pond in the future.
Velda also has the Laser Guard in the range. With a.o. laser beams, it is a very effective product against herons and other threats to fish. See here for the entire range of heron scarecrows.
This can have a number of causes. The oxygen plants are not getting enough sunlight, they are too deep in the water or the hardness of the water is not good enough. Make sure you have oxygen plants at the right depth and that they get at least 6 hours of sunlight a day. In addition, test the hardness of the water. If it is too low, increase it with GH Plus. If you are suffering from green algae that prevents sunlight from reaching the oxygen plants, you must first correct that problem.
If you suffer from a lot of bottom silt, we recommend using Bio-Oxydator. Bio-Oxydator removes bottom silt and prevents new silt formation.
Especially in small shallow ponds, fish death by suffocation occurs frequently when the pond freezes over. However, never cut a hole in the ice, because the vibrations are harmful to your fish. Aeration of the water is better then. The air bubbles keep the pond ice-free and the water rich in oxygen.
A UV-C needs about 2 weeks to work optimally
Yes, as long as it does not freeze, the filter can continue to work as usual. In case of frost (down to -10 C), you can install a heating element in the filter to keep your filtration system running. The warm water keeps the pond locally ice-free, stimulates micro-life and prevents a backwash in early spring.
The easiest method is to make a drawing of the pond, then use a tape measure to measure the pond. You can then use the following rule of thumb:
Incorporate the measurements thus obtained into the drawing. Then the garden center or pond specialist can calculate for you how much pond liner you will need. Click here for a handy step-by-step plan for building a pond.
After purchase, immediately transfer the pond plants into planting baskets about 30% larger than the growing pots. For coarse-mesh planting baskets, use an insert. Replenish the baskets with a special nutrient soil tailored to the plant needs and cover the soil with a layer of pond gravel. Slowly lower the baskets into the pond and place them at the proper depth (indicated on the label).
Yes, sediment from organic matter is a food source for algae and can cause explosive algae growth in the spring. Remove fallen leaves with a scoop net and stretch a cover net over the pond to prevent leaves and twigs from blowing in.
The guideline per 1000 liters of water is: 5 bushes or 3 pots of oxygen plants + 6 marsh/bank plants. For example, for a 5,000-liter pond, count 10 bushes + 9 pots of oxygen plants and 6 groups of 5 marsh/bank plants. Supplement the plant stock with 1 or 2 water lilies, matched to the pond size, and floating plants as desired. At least 50% of the pond area should eventually be overgrown with aquatic plants for a healthy pond.
Reduced water output from the pond pump can be due to:
Pond substrate is a porous rock full of microscopic spaces in which water-purifying bacteria settle and multiply. These beneficial bacteria break down organic waste products and provide biological balance in the pond environment. A dose of Bacterial accelerates this process
One short-term solution is to use All Clear Powder .Keep in mind that this will not fix the problem for the long term. Green filamentous algae are in fact also aquatic plants, but with a simple structure. However, they can proliferate enormously and bind large amounts of nutrients in the process. Long-term solution is to add more marsh plants and water lilies: cover the water surface 30-40% with floating plants. The aquatic plants absorb the nutrients, which will reduce algae growth. Make sure the total hardness (GH value) of the water is at least 12 °DH. Remove string algae from the pond regularly and as much as possible. As the plant stock grows and increases in size, the growth of filamentous algae will decrease: the primary growth of these algae will be taken over by the growth of aquatic plants over time. By purchasing a T-Flow Tronic, an electric thread and slime algae controller, you are guaranteed a long-term solution.
Only after a week or two the output of the UV-C PL lamp is optimal. This is a normal process for this type of lamp. With continuous use, the effective life of the UV-C lamp is about one year. Preferably replace the lamp in the spring and also clean the quartz glass. Order new parts easily online at www.vijverproducten.shop.
Bio-Oxydator is not harmful to your fish, plants or pond. Bio-Oxydator contains a water hardening agent (including lime) to slightly increase the hardness of the water on the bottom and a bacterial culture for breakdown of organic waste on the bottom.
This product, which Velda has had in its range for a long time, is not harmful even when overdosed.
Velda maintains a maximum capacity for the Cross Flow Biofill so that too much pressure does not build up in the filter and the filter does not leak. Therefore, the following conditions apply:
The net pumping capacity depends on the length and height of the pump to the filter. If the water has to travel a considerable distance and height, the net capacity will be a lot less
If the pump has too much capacity, you can reduce it by installing a T-piece that allows some of the water to flow directly back into the pond. The amount of water can be regulated by the outlet diameter of this branch.
We recommend turning off the filter in winter to prevent broken freezing. The rest of the year, the filter should be left on day and night.
A bacterial culture forms in the filter that keeps the water clean, while the UV-C lamp kills the algae. The bacteria die when the filter is off for a few hours and then must re-form when it is back in operation.
In combination with the Cross-Flow Biofill we recommend the Green Line pump 5000 recommended. It has low energy consumption and long life.
If another pump is already present, we recommend the following:
Velda maintains a maximum capacity for the Cross-Flow Biofill so that too much pressure is not built up in the filter and the filter does not leak. Therefore, the following conditions apply:
The net pumping capacity depends on the length and height of the pump to the filter. If the water has to travel a considerable distance and height, the net capacity will be a lot less.
If the pump has too much capacity, you can reduce it by installing a T-piece that allows some of the water to flow directly back into the pond. The amount of water can be regulated by the outlet diameter of this branch.
Leaking with the Cross-Flow Biofill is almost always related to pressure building up or a larger amount of water flowing through the filter than the filter can handle. Since it is not a pressure filter, this must be prevented. Here are some points to check why the Cross-Flow Biofill is leaking:
The maximum flow capacity of the Cross-Flow Biofill is 5000 l/hour. If the net output of the pump is more than 5000 l/hour, the filter cannot handle this and will leak. You can reduce the net output of the pump by placing a T-piece in the hose and allowing some of the water to “leak” directly back into the pond. The distance from the pump to the filter and especially the height difference between the pump and the filter also affect the net output of the pump. The greater these are, the lower the pump’s output.
Check that the ring in the rim of the lid is properly placed. However, this ring cannot handle much water pressure. If the Cross-Flow Biofill is higher than the water level, the chance of leaks is less
Regardless of the filter, green water (floating algae) should become clear with a UV-C Unit. Only if the pond is old with a lot of organic material on the bottom and an acidified environment will this not work.
The effective life of a UV-C lamp is approximately 7500 hours of operation. With continuous use, the lamp will therefore last a pond season. It is recommended to replace the lamp every spring.
In addition, it is wise not to keep too many fish in the pond.
This is because the Cross-Flow Biofill is not a pressure filter you need to prevent too much pressure from clogging the filter, for example.
The water cannot then flow sufficiently, causing the lid to bulge. Regular rinsing of the filter material will solve this problem. You can possibly order a new lid from the Velda parts shop.
Chances are that the conductivity of the water is too low and this can be measured by taking a mug of water and dissolving about 20 grains of salt in it. Then dip the green endcap with anode and cathode in it (the display must still be connected). If the error message disappears, the conductivity is too low. Increase the conductivity by adding GH plus or Mineral plus to the pond water.
Velda guarantees the correct functioning of all its technical products for a period of 2 years after purchase. When you register your purchase for warranty with Velda, we can ensure faster handling in case of a problem or defect. Please keep the original purchase receipt and report the defective product to the point of sale where it was purchased to claim warranty.
If a Velda product does not function properly, you can of course appeal to our warranty conditions. Velda guarantees the correct functioning of all its technical products for a period of 2 years after purchase.
If a Velda product does not function properly, please refer to the manual. Replacement parts such as filter materials, UV-C lamps and hose grommets can be easily ordered online at www.vijverproducten.shop or ask for them in the specialist trade.
This can have several causes you should look into. The water lily is too deep, too close to a pump or waterfall, in too small a basket or it is in the wrong soil. If it is too deep or too close to a pump or waterfall, move the water lily. If the water lily is in a basket that is too small, repot the water lily in a larger basket and fill the basket with special soil or substrate for the water lily. Keep in mind that water lilies do not bloom until late in the season, especially the flowers.
