Choosing a Filter System

Your pond water quality will be effected by a number of factors including fish waste, uneaten food and plant matter. If this debris is allowed to accumulate it can, in time, become harmful to the fish or you may get large algae blooms. Biological Filtration systems are a great way to keep your pond clean. There are two main types of filtration, the mechanical filtration and the biological filtration. Mechanical filtration is the removal of particles by filter matting or brushes which is the part of the filter which you need to clean. The Biological filtration is generally seen in the form of bio balls or media located in the bottom of the filter. The bio balls should not be cleaned as the good bacteria will colonise on them and if they are cleaned with tap water it will kill all the good bacteria that has accumulated. Good bacteria is essential in your pond system as it converts toxic pollutants into nitrate which is a main growing ingredient for plants. Extra water clarity can be obtained using an Ultra Violet Light which is often incorporated into the filter.

Filters are normally paired with a Dirty Water Pump, which can take bigger particles through the impeller and straight through to the filter. There are two types of filters - Gravity and Pressure.

Pressurised Filters

Pressurised Filters have an advantage as they are sealed units meaning they can be placed above or below the water level. This makes them a lot easier to hide. Most pressurised units come with a UV unit built into them. UV lights stop that pea-soup green pond water from forming. It will kill the suspended algae as the UV light clumps the algae cells together so that it drops from suspension and can be filtered out of the pond. Although it stops the pea-soup green water the UV clarifier will do nothing to kill string algae or blanketweed.

Gravity Filters

Gravity Filters come in a few different shapes and sizes but they all need to sit above the pond so they can pour the filtered water back into the pond. Most gravity filters do not come with a UV light but the UV light can be put in-line as you can buy the UV clarifiers on their own.

All Filters have a recommended maximum flow rate they can take through them. You don’t want too much flow rushing through the filter, and gravity filters will overflow if you exceed the recommended maximum flow rate. High pressure pumps such as retic. pumps or sump pumps are not recommended.

IMPORTANT POINTS:

• Continuous Flow – Filters need to be running 24/7. If you turn your filter off for a period of time you will kill any good bacteria that has established. The good bacteria needs to have a continuous flow and oxygen in order to survive. Bacteria can take months or years to build up properly in a pond.
• Circulation – To get the best filtration you need to allow all the pond water to pass through your filter. To allow this you need to have your pump at the opposite end of the pond to your filter to fully circulate the pond.
• Equipment – Make sure to get the correct equipment based on your pond volume and the type of fish you want. If unsure always go bigger.
• Fish Stock – If you overstock the pond you will need to oversize the filtration to suit. Even if you are starting small you have to remember that the fish will grow so you will need to allow room for growth.
• Feeding – Fish can be described as opportunistic eaters this meaning they will take any chance they can to get food. Overfeeding can have massive impacts on your fish, filtration and the water quality.
• Pollutants / Debris – Be careful when spraying around the pond as this can affect the water quality. Also when potting pants and placing them in the pond. You want to use a soil with low fertiliser levels as this can affect the water quality too. It is a good idea to scoop out any leaves or debris that fall into the pond as this will break down into ammonia which is toxic to fish.
• Plants – Plants help maintain the eco-system. They will provide oxygen and shade, as well as remove nitrates from the water. You can build streams or spillways and cover them will plants to create a plant filter.

Please contact us for more information on what system may be best for you!