Removing Pond Sludge | Viresco Pond Digester Is A Great Pond Sludge Treatment
I recently received a query from the owner of a large pond. The volume was some 50,000 litres (10,000 gallons in US) and he was sick and tired of the sludge at the bottom of his fish pond and was looking for a a good fish pond sludge treatment solution.
He wanted to know what type of pond filter is the best for removing pond sludge and for keeping the bottom of his fish pond clean.
This query once again reminded me that the vast majority of pond keepers see a filter as having the job of removing solids.
It is not surprising since filtering of anything is normally associated with removing solids from a liquid.
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A BIOLOGICAL FILTER IS NOT A TRADITIONAL FILTER
In a pond environment we should always therefore speak of a biological filter and the most important job of a biofilter is NOT to remove solids but to purify the water in which the fish live.
In a garden fish pond where there is no biological filter many things can and do go wrong and the worst that can happen is that all the fish die from either poisoning or disease.
The following is what's important to understand...
A fish, through its normal metabolic processes, actually pollutes the water in which it swims.
The pollutants are nitrogen based chemicals in either ammonia or nitrite forms. The biological filter converts the ammonia and nitrites to nitrates which is relatively harmless to fish although nitrates are responsible for murky water and blanketweed.
Incidentally a great algae and pond sludge treatment, including murky water and blanketweed is Viresco.
A biological filter is used as a place to hold large colonies of bacteria which cling to surfaces inside the biofilter such as plastic tubes, foam or balls.
In the USA a low cost and extremely good pond filter media is Supra by Fishmate.
These bacteria remove the pollutants from the water as it is pumped through the filter.
Now the filter will actually remove some solids but it will be a small percentage of the solids that find their way into a pond.
Solids in a pond come from wind borne debris, too much fish food, rain run-off and fish feces.
These solids normally settle quite quickly on the pond floor and are not picked up by the pump. As a result over time a sediment consisting of organic and inorganic debris builds up on the bottom of the pond and after years this can become what is known as pond sludge or pond silt.
Pond sludge encourages the growth of heterotrophic bacteria that may eventually lead to the appearance or increase in Fish Health Problems and Fish Diseases.
Fish Pond Sludge Treatment Solution Methods...
Use Bacterial Digesters ...
These are bacterial digesters available that have been designed to break down pond sludge. These are known as "sludge busters", "sludge digesters" or "pond silt removers".
They do work but are more of a quick fix than a total solution. Microbe-Lift Autumn Prep and Microbe-Lift Spring Cleaner are two popular brands in the USA.
Viresco Pond Digester, a British product that is shipped world wide and has been designed to control the formation of blanket weed (string algae/ hair algae) and algae and is also very good at removing pond sludge.
Empty The Pond Annually...
For people with small ponds it is not too big of a job to empty the pond every year or so but if the pond is large then emptying the pond is no small job and not recommended.
Bottom Drains Work...
Every large pond should be built to include a bottom drain... such a system allows solids in the pond to accumulate at the drain point.
The solids are thus continuously removed with the re-circulating water that is sucked from the bottom drain.
Solids are then removed in a settling chamber of some description (a vortex unit is the most efficient).
The settling chamber is then purged occasionally.
This results in a pond with no debris build up.
A Pond Sludge vacuum Works If No Bottom Drain...
Of course the above doesn't help if the pond has already been built which really only leaves one option other than emptying the pond and that is to use a specially designed and safe to use fish pond sludge vacuum cleaner.
Take a look at the Pond Vacuum Cleaner Reviews on this site...
The three most common types of pond and sludge vacuum cleaners are electric mains powered pond vacuums, hand powered pond vacs and water powered pond vacuum cleaners that attach to your domestic water supply via a hose pipe. The first two types are the most common type.
If you intend to regularly vacuum your pond floor then the less powerful hand operated or water powered pond vacs are the better choice. They have been specifically designed to deal with smaller volumes of fish pond sludge and often come with a brush attachment for rubbing down pond ornaments and water features.
Electric pond vacuum cleaners are more powerful and designed to reach even the deepest parts of your fish pond. They are capable of removing large quantities of pond sludge that has been allowed to form over the years.
Pond sludge vacuum cleaners also come in handy should you wish to carry out a partial water change.
Pond Snails Eat Fish Pond Sludge
Yes you can use Pond Snails to remove sludge and other decaying matter and vegetation from your pond floor. This would require a large number of snails unfortunately and is not the best way to solve this problem.
IN SUMMARY AND WHAT'S IMPORTANT TO KNOW...
Trying to prevent pond sludge from forming altogether is almost impossible but the following tips will certainly help to reduce the build up significantly...
- Solids will build up in any pond without a bottom drain.
- Don't overfeed Fish Food and only feed floating pellet fish food and remove any uneaten food after about 10 minutes; this prevents the food from sinking and forming sludge on the pond floor.
- Use a Pond Net to cover your pond so as to prevent leaves from nearby trees etc from falling into the pond.
- Don't add rocks or pebbles to the floor bed of your pond as they make cleaning the pond more difficult and trap debris causing sludge to form.
- A Pond Pump and Biological Pond Filter alone will NOT prevent solids building up and eventually becoming pond sludge.