Colombo Clean Sludge Bacteria

Bactuur Clean Sludge by Colombo is a liquid product containing live bacteria that break down sludge accumulated at the bottom of the pond and in the filter. It is suitable for both cleaning a silty pond and its regular maintenance, and it helps maintain the filter's biofilm. It works gradually: it complements sludge removal and good filtration without replacing them.

Sludge is one of the most common problems in garden ponds. It accumulates silently, season after season, and eventually clouds the water, consumes oxygen, and releases nutrients that benefit algae. Experts in aquatic environments since 1998, we present this product, how it works, and the best way to use it.

What exactly is Clean Sludge?

Colombo is a Dutch brand specializing in products for ponds and aquariums. Its Bactuur range includes bacterial products, each with a specific role. Bactuur Clean Sludge, literally "sludge cleaning", is the one that targets sludge.

According to the product sheet, each milliliter contains 100 million live bacteria. These bacteria break down the sludge accumulated at the bottom of the pond and in the filter, and maintain the filter's biofilm, this thin living layer that ensures biological filtration. The product is therefore suitable for both bottom cleaning and regular maintenance.

Where does sludge come from in a pond?

Sludge is a mixture of decomposing organic matter and mineral particles. Its sources are numerous: tree leaves, pollen, withered plants, food scraps, fish waste, dust brought by the wind and rain. In a balanced pond, part of this matter is naturally degraded by bacteria. When the inputs exceed the degradation capacity, a layer forms at the bottom.

This layer poses several problems. Its decomposition consumes oxygen, especially at night and in summer. It releases nitrogen and phosphorus into the water, which feed the algae. In the thickest areas, deprived of oxygen, it can produce foul-smelling gases. Finally, it clouds the water every time it is stirred.

How do anti-sludge bacteria work

The bacteria in Clean Sludge are microorganisms selected to feed on organic matter. Added to the pond, they attach to the bottom, the walls, and in the filter, where their food is located. They gradually break it down into simpler elements. Part is then consumed by the plants, part returns in the form of carbon dioxide and water.

This work takes time. Do not expect to see the sludge disappear in a few days: an evolution is generally observed over several weeks, the clearer the water is tempered and well oxygenated. Bacteria need oxygen to work effectively; an air pump or good water circulation helps them.

For which ponds?

Clean Sludge is intended for garden ponds, with or without fish, and their filters. It is particularly useful in the following situations:

• Pond under trees, which receives a lot of leaves every autumn.
• Well-stocked fish pond, where waste and food scraps accumulate quickly.
• Old pond, never cleaned, whose bottom has gradually become loaded.
• Filter that clogs quickly: bacteria help break down the organic matter trapped in the sponges and supports.

For a large natural pond, several hundred cubic meters, other products packaged in large volumes are generally more suitable: ask us for advice by specifying the surface and depth.

How to use Bactuur Clean Sludge

1. Check the water temperature. Bacteria are active when the water is sufficiently tempered; follow the instructions on the packaging.
2. Turn off the UV-C during the recommended period after addition, so that the bacteria are not neutralized in the device.
3. Dose according to the volume of your pond, following the label. The volume indicated on each size (2,500 liters for 500 ml, 5,000 liters for 1,000 ml) helps you choose the bottle size.
4. Distribute the product in the pond, preferably over the most silty areas, and part in the filter if the instructions provide for it.
5. Leave the filtration running and the aeration working.
6. Renew according to the indicated frequency, first as a bottom treatment and then for maintenance.

Bacteria or vacuum: which to choose?

The two approaches do not oppose each other, they complement each other. The vacuum immediately removes the accumulated matter; the bacteria take care of what remains and what continues to arrive.

In practice, we often recommend vacuuming in spring or autumn, before winter, followed by bacterial treatment during the season. For details, see our guide sludge in the pond: vacuum or use bacteria?

Limiting the return of sludge

An anti-sludge treatment is all the more effective when we reduce inputs. A few simple gestures make a big difference:

• Place a net over the pond in autumn, if trees overhang it.
• Remove leaves and withered plants before they sink.
• Feed the fish moderately, adapting the rations to the water temperature.
• Clean the filter with pond water, without sterilizing everything, to preserve its bacteria.
• Install enough aquatic plants, which capture part of the nutrients.
• Oxygenate the water, especially in summer, so that decomposition takes place under good conditions.

With a cleaner bottom and fewer nutrients released, the water becomes less favorable to algae: it is one of the most visible consequences of a rebalanced pond.

The mistakes that reduce effectiveness

• Treat in cold water: bacteria remain almost inactive and the product is wasted.
• Leave the UV-C on just after addition: part of the bacteria is neutralized as it passes through the device.
• Clean the filter with tap water the day after treatment: chlorine and complete rinsing destroy the bacterial flora that had just settled.
• Combine with a fish care product that acts on microorganisms: wait until the end of the treatment and the indicated time before adding bacteria.
• Expect a result in a few days: the decomposition of a layer of sludge is a slow process, judged over several weeks.

The other products in the Bactuur range

Colombo offers several complementary products in the Bactuur range. Filter Start is used to start or restart biological filtration in spring and after each filter cleaning. Clean Sludge focuses on sludge and biofilm maintenance. Combining them in a seasonal program allows covering both the filter startup and bottom maintenance. Find the entire range in our collection Colombo Bactuur.

Frequently Asked Questions

What is Bactuur Clean Sludge used for?

To reduce sludge. Its live bacteria break down the sludge accumulated at the bottom of the pond and in the filter, and maintain the filter's biofilm.

How long does it take to see a result?

The action is gradual: count several weeks, depending on the thickness of the sludge, the temperature, and the oxygenation of the water.

Is Clean Sludge compatible with fish and plants?

It is a biological product intended for stocked garden ponds. Respect the dosage indicated on the packaging.

Should the UV-C lamp be turned off?

Yes, it is recommended to turn it off during the recommended period after adding bacteria, to give them time to settle.

Should sludge be vacuumed before using Clean Sludge?

If the layer is thick, yes: vacuuming removes most of it immediately, and the bacteria then treat the rest.

Can Clean Sludge be used in winter?

In cold water, bacterial activity is greatly slowed. It is more useful to use it from spring to autumn, when the water is tempered.

Also read

• How to vacuum sludge from a pond?
• Should the UV be turned off when adding bacteria to a pond?
• How to avoid sludge in a pond?