ProfiClear Premium Screen: 60 or 150 microns? Identify and replace yours

Sooner or later, every drum filter reaches the point where the filter mesh is worn, torn in places, or clogged with limescale to the extent that rinsing is no longer enough. On an OASE ProfiClear Premium, you must then order a replacement screen set. And this is where many people get stuck: 60 or 150 microns? Nothing looks more like one fine stainless steel mesh than another fine stainless steel mesh. In the vast majority of cases, an original ProfiClear Premium is equipped with 60 µm screens, the standard mesh fineness; 150 µm is an option that is chosen deliberately. Here's how to verify it with certainty and how to determine whether changing the mesh fineness is worthwhile.

How the screens in a ProfiClear Premium work

A drum filter is a mechanical prefilter. Pond water enters the center of a cylinder covered with very fine stainless steel mesh and flows out through the mesh. Particles larger than the mesh openings remain trapped on the inner surface. When the mesh becomes clogged, the water level changes between the inside and outside of the drum; a sensor detects this, the drum rotates, and nozzles spray pressurized water to dislodge the dirt into a discharge chute. This cycle repeats automatically.

On the ProfiClear Premium, the drum surface consists of 8 removable screen elements, each with its stainless steel mesh, seal, and fastening clips. This allows them to be replaced without replacing the entire drum. The mesh fineness, expressed in microns (µm, thousandths of a millimeter), determines the size of the particles captured.

To properly understand the drum's role in the overall filtration system, our article on the 4 pillars of a balanced pond explains how prefiltration, biological filtration, and oxygenation work together.

60, 150, 30 µm: what really changes

OASE presents the 150 µm screen as a coarser pre-separation than the standard screen, allowing smaller particles and microorganisms to pass through, and recommends it especially for natural ponds and swimming ponds: the aim is to retain some of the microscopic life and limit discharged water. Conversely, a densely stocked koi pond generally benefits from the standard mesh size, or even 30 µm if you want crystal-clear water and accept more frequent rinsing.

The choice of mesh size is therefore not a question of quality but of use: a finer screen is not absolutely “better”; it simply shifts the balance between clarity and water consumption.

Five ways to find out whether your screens are 60 or 150 µm

1. Start with the filter's history

If the filter has never received replacement screens since it was installed, it most likely still has its original screens, meaning 60 µm. A 150 µm screen will only be found on a drum if someone ordered and installed it.

2. Find the invoice or reference number

If any screens have already been replaced, the invoice or purchase order will settle the question. At OASE, screen sets have different reference numbers depending on the mesh size: for example, 25376 for the 60 µm set, 50947 for the 150 µm set, and 51549 for the 30 µm set. If your installer carried out the replacement, they kept a record of the order. If the filter was bought second-hand, ask the previous owner.

3. Compare the mesh with a magnifying glass or smartphone

This is the most telling method when you have no documentation. Remove a screen, rinse it, and look at the mesh against the light with a good-quality magnifying glass or a smartphone's macro mode. A 150 µm opening is approximately two and a half times wider than a 60 µm opening: the difference is easy to see when you can compare the two. To give you a sense of scale, a human hair is roughly several dozen to one hundred microns thick. Placed on the mesh, it covers more than one opening on a 60 µm screen, whereas it is roughly the same size as an opening on a 150 µm screen. This test remains indicative, but it can often settle the question.

4. Observe the drum's behavior

With comparable pond conditions and season, a drum fitted with 150 µm screens rinses noticeably less often than one fitted with 60 µm screens. If your filter triggered frequent rinses in summer and you have never changed anything, this is consistent with 60 µm screens. This criterion alone is not enough, because the pond load greatly affects the frequency, but it confirms the other clues.

5. Check the frame and documentation

Inspect the frame of each element and the original packaging if you kept it: it may contain a label or reference number. The filter manual also specifies the standard equipment. And if you are still unsure, send us a clear close-up photo of the screen with a ruler or a hair placed on it: we will help you identify it.

Replacing the screens: the right steps

1. Switch off the power to the pump and filter, and allow the drum to stop completely.
2. Open the cover and roughly clean the inside so you can work cleanly.
3. Unclip one element at a time, turning the drum by hand to access the next ones. Note the installation direction of the first one so you can install the others the same way.
4. Check the seals and supports: a poorly positioned seal allows unfiltered water to pass through the side, negating the benefit of a new screen.
5. Clip the new elements into place, checking that each one is properly seated all the way around.
6. Restart and observe one or two rinse cycles: the drum should rotate smoothly and the nozzles should sweep across the entire width of the screen.

Take the opportunity to check the rinse nozzles. Nozzles partially clogged with limescale are a common cause of screens clogging prematurely: replacing the screens without addressing this issue means finding the same problem again a few months later.

Should you take the opportunity to change the mesh size when replacing it?

That is the right question to ask, since sets of 8 screens are available in several mesh sizes and are installed in the same way. Here are a few guidelines:

• Heavily stocked koi pond, sometimes cloudy water: stay with 60 µm, or consider 30 µm if your make-up water supply can keep up and water consumption is not a concern.
• Natural pond, swimming pond, or low fish population: 150 µm is often more suitable, with less rinsing and prefiltration that allows the rest of the ecosystem to work.
• Water consumption or the water level dropping too quickly in summer: switching from 60 to 150 µm reduces rinsing frequency.
• Water heavily loaded with fine particles (silt, suspended algae): the screen alone will not solve the problem; also consider UV-C, biological filtration, and circulation.

Changing the mesh size alters the balance of the entire filtration system. If you switch to a coarser mesh, the next stage (foam, moving bed, matting) receives more fine particles: plan to monitor clogging during the first few weeks. Our article on Japanese mats for pond filters explains the role of these fine mechanical filtration stages.

When should screens really be replaced?

A well-maintained stainless steel screen lasts a long time. Replace it when one or more of these situations occur: the screen is perforated or has detached from the frame, deformation prevents it from sitting correctly on the seal, persistent clogging despite thorough cleaning, or rinsing has become unusually frequent even though the pond has not changed. Before deciding to replace it, try a thorough cleaning: gentle brushing, possibly descaling with a product suitable for stainless steel, followed by abundant rinsing. A simply scaled-up screen often regains much of its capacity.

To extend the time between replacements, a few habits help considerably. Inspect the mesh at every major spring and autumn maintenance, with the drum stopped. Monitor the pressure and condition of the rinsing nozzles, since they are what keep the mesh clean. In hard-water regions, limescale gradually deposits on the stainless steel and reduces the useful filtering surface: preventive descaling once a year prevents clogging. Finally, never handle the elements by the mesh itself: hold them by the frame, as finger pressure is enough to deform such a fine mesh. Also keep a set of spare seals, since a worn seal compromises the watertightness of an otherwise perfectly sound screen.

Also read

To understand the technical choices involved in a drum filter: How to choose a drum filter for a pond?.

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Frequently asked questions

— What mesh size is factory-fitted on a ProfiClear Premium?

The 60 µm, which is the standard mesh size for the drum module. The 150 µm and 30 µm are options.

— How many screens are needed to equip a drum?

Eight elements. Replacement sets are sold in packs of 8 so that the entire drum surface can be replaced at once.

— Can screens with different mesh sizes be mixed?

This is not recommended: the drum would filter unevenly, and water would preferentially pass through the more open elements. Equip the entire drum with the same mesh size.

— Does 150 µm produce less clear water?

It stops fewer fine particles, which pass to the next stage of filtration. In a natural pond or swimming pond, this is often intentional; in a heavily stocked koi pond, 60 µm generally remains more suitable.

In summary

• The ProfiClear Premium comes from the factory with 60 µm screens.
• The 150 µm is a coarser option, designed for natural ponds, swimming ponds, and reducing rinsing frequency.
• To identify your screens: history, invoice and reference, comparison with the macro, rinsing frequency.
• Replace all 8 elements together, checking the seals and rinsing nozzles.
• Replacement is an opportunity to consider the most suitable mesh size for your pond.

Last updated: October 3, 2026.