POND VEGGIE (PLANT/BOG FILTERS); The four basic types of veggie filters and how to install them.

Updated 7/17/11




SECTIONS;

• Overview
• Suggest Bog Plants
• Additional Tips
• Veggie/Bog Filter Methods of Construction
1. Corner
2. Constriction
3. Waterfall
4. Separate Veggie Filter
• Conclusion/Summary

OVERVIEW

Bog Plant or “Veggie Filters” are very popular with many pond keepers. I have been using this method for pond filtration for a few decades (long before the term veggie filter became popular). Veggie (plant) filters are excellent for removal of many nutrients that cause green or cloudy water (including nitrates, phosphates, etc.). A well constructed Pond Veggie/Bog filter can also help control hair/string algae as well by robbing many of the nutrients from this algae.

There are two basic methods (that I am aware of), the more popular method nowadays is a separate pond filter. This is not my preferred method, however both work very well (I will discuss each latter). Any plant with a good root structure that grows fast and has the majority of their leaves above water (basically a bog plant) is a good candidate to start with. I recommend water iris for their strong root structure, fast growth, great nutrient absorption, and a great place for baby fish (fry) to hide feed and grow.

I prefer my Bog-plant filters within the pond as these look more attractive in my opinion and give the fish fry a place to hide (except in the case of the waterfall or cascade plant filter).
The area of the veggie filter should be relatively shallow as well to force water movement over and through the roots
There are many other excellent plants as well such as Sweet Flag, Parrots feather, Bluebells, Umbrella palm, Papyrus, & bull rush. Make sure these types of plants (plants with roots in water and leaves above) are planted in an area of good, but not strong water movement. This ensures that they will do their job as plant filters.

Please note that having a few Water Iris, Umbrella Palms, etc in a pond does NOT constitute a Veggie (Plant) Filter. For these plants to work as a filter you must have a small current of water around the roots or tubers, as well the use of substrate such as Volcanic Rock further increases filtration by allowing for the propagation of nitrifying and de-nitrifying bacteria as well as some mechanical filtration as well (trapping of debris). The mechanical aspect can be further increased by the addition of coarse polyester filter pads in the water column entering the Veggie Filter.
Often person will consider many floating Lilies a Veggie Filter, however they do not constitute a Veggie Filter, as although they certainly help block sunlight and remove some nutrients form the water column (which in turn can help control green algae), Lilies or other floating plants due not have the substrate roots, effectively remove nutrients and work with the substrate around them the way a true Veggie Filter can that uses Bog Plants.

A FEW SUGGESTED VEGGIE FILTER/BOG PLANTS (& Online Sources to purchase them)

Water Iris
Water Iris
This website here in Oregon ships beautiful Water Iris that can be used in your Water Garden, Pond; in particular your Veggie/Plant Filter.

The Water Iris is my personal Favorite, and grows in most climates from mild winters to more harsh winters (check individual specimen). Several varieties of Iris thrive in water gardens. I enjoy their graceful upright leaves and elegant blossoms. Iris flowers are several inches across and appear in early to late spring (depending upon climate) and dead blossoms should be clipped so as keep plants looking good and healthy. The plants will spread and form large tubers if given enough room. The yellow water Iris requires full sun, but the other varieties will bloom if they receive a minimum of three hours of direct sunlight, although they may become spindly.

Umbrella Plant
Umbrella PalmThis is tropical bog plant, but can be grown in some cooler climates (such as high deserts of California if a freeze is not too hard).
Stems are 3-4 feet tall with the classic “umbrella (similar to the Dwarf Papyrus except the foliage is broader and the stems are taller). Best grown in full sun, partial shade, or filtered light. Plant Umbrella Palms in wet soil or in water up to 6 inches deep. For cooler climates it can be over-wintered as a houseplant if kept wet and given enough light.
The Umbrella Palm can take over a pond if not contained, so either use pots or keeping them strictly in sectioned off Veggie Filter.



Arrowhead
Arrowhead

Another popular bog plant for pond veggie/plant filters.
Arrow head pond plants grow 2-3 feet tall in full sun and have large leaves and small white cupped flowers. These are best planted in 2" inches of gravel/fine volcanic rock in your Veggie Filter, with no more than 6" inches of water over the base of the plant or in pots with good top soil covered with gravel. Best in full sun or in partial shade.

A FEW TIPS

I recommend starting your veggie filter plants in pots (I prefer ceramic or even the bio degradable type) as these will contain the plant roots in the beginning, yet allow growth of the roots out of the pots. I highly recommend using Volcanic Rock in the area around the pots to fill in the gaps and allow for additional filtration. The advantage of volcanic rock is that its porous structure allows formation of aerobic bacteria for nitrification and anaerobic bacteria for de-nitrification. This further enhances your veggie filters ability to keep a clear pond by removing the nutrients necessary for green water/algae. The volcanic rock is also an excellent growth substrate for the plant roots as your veggie filter grows.

If water movement is poor in the area of your Veggie Filter (plant roots), I would recommend a submersible pump placed near the veggie filter with its outflow aimed at the veggie filter. Make sure this current is not too strong, so angling the outflow if the current is causing too much disturbance of the roots, volcanic rock, etc. Another way to circulate water in the area of an in pond Veggie Filter is to add a fountain to your submersible pump so as to have a more gentle spray in the area of the plant/veggie filter. I generally use a pump with a flow around 500 -1000 gph around veggie filters in a pond of approximately 300- 1200 gallons (this may be increased or decreased depending on the pond size). The Via Aqua 2600 is an excellent pump for use here with a flow of 740 gph. Other suggestions include the Via Aqua 3300 or the Via Aqua DP-18000 Multi Duty Pond Pump for larger water flows or multiple applications.

Be patient with a veggie filter as unlike many other forms of pond filtration, a veggie filter takes a while to become effective (often a FULL growing season!). This is why it is a good idea to have additional filtration as well such as a Pressurized Pond Filter and a UV Sterilizer

VEGGIE FILTER METHODS & CONSTRUCTION:

Before the common methods are discussed, let me point out some basics in construction that is common to all.

First is sizing, generally I have found a Veggie filter that consists of not only the plants/roots, but also has 6-12 inches of volcanic rock in the root/substrate area (there are even more advanced designs than this too) will work vastly better than several potted or otherwise randomly placed bog plants (due to added filtration by bacteria and the trapping of debris for plants to also more easily utilize). Assuming this combination of plant roots and tubers I have found that a mature Veggie (plant/bog) Filter of about 10% in surface volume as compared to the surface volume of the pond works well.
I have found that surface area works fine as compared to other calculation methods (which work too), as it is often the surface area that determines gas exchange & sunlight exposure. I will admit that this method of calculation does not take into consideration fish numbers, but considering average depths of 2-4 feet and healthy stocking numbers this has rarely failed me in calculations.

Some sub-methods of these basic designs include pulling water through the Veggie Filter bottom or pushing it upwards using slotted PVC. This idea certainly has the advantage of increasing flow to the roots and aerobic bacteria for ammonia/nitrite removal, however the downside can sometimes adversely affect some plant roots/tubers and often does not allow for de-nitrifying anaerobic to propagate for important nitrate removal (which is important for green water control). For this reason I do not promote this method of construction.

For me a better advanced addition to these methods (listed below) is to add an egg crate (or similar) before water enters the Veggie filter to support a pre-filter of coarse filter media and sometimes micron filter media as well. For corner Veggie Filters (or others) the use of a spray bar where the pump irrigates the water over this pre-filter works well too.




[1] Corner;
Place your plants in a shallow corner of the pond with ½” -2” rock under the plants to allow the roots to better establish themselves, do not use sand or soil. The water depth is best if the roots are barely covered by water. Add a slow to moderate (200- 600 gph) separate water supply (a diversion from your main water pump or a separate pump) to these plants make sure the water passes through the plant roots, not just over them.
An air pump such as a Fusion 700 or Million Air 600 can also be used and placed in the middle to draw water in via the rising air column.

[2] Constriction;
Similar to above, place your plants in a shallow corner of the pond with ½” -2” rock under the plants to allow the roots to better establish themselves, do not use sand or soil. The water depth is best if the roots are barely covered by water. In this case, allow the water to move from one pond to the other thru this constriction area in a manner that maximizes root exposure to the water flow (again, not high a flow)

[3] Waterfall;
In this method the plants are in the waterfall or cascade area of the pond (or just prior to this area). Again place your plants in a shallow corner of the pond with ½” -2” rock under the plants to allow the roots to better establish themselves, do not use sand or soil. The water depth is best if the roots are barely covered by water. This method can be combined with other methods.

With this method I recommend the use of some loose fitting bricks or slightly more tight fitting rocks to contain this filter (plant roots/tubers and volcanic rock). These rocks/bricks can be used to contain this filter on boths sides(upper falls/pond side and cascade/waterfalls side). The use of rocks or bricks is also useful for constriction or corner Veggie Filters.

The downside to this method if used by itself is it does not give the fry a place to hide and often water flows and water depths are harder to control for maximum efficiency, however this method still works especially when used in combination. The upside is the simplicity of design since the natural water movement will pull water through this filter.



[4] Separate Veggie Filter;
This is a more popular method lately, although my least favorite.
In this method you would use a container such as a tub or small pool and pump water into these “Plant Filers” then water flows back into the main pond. I have seen nicely set up separate veggie filters where they are actually constructed into the ground or into a terrace, these do look better than the tub methods (these are more similar to the waterfall method). My problem with this method is similar to the waterfall method in that flow around the roots and water level (just above the roots) is hard to control to maximize benefits of the plant root structure. You also loose the benefit of a place for fry or breeding adults to hide as in the first methods.

CONCLUSION;

A Veggie or Plant Filter is an excellent compliment or even stand alone pond filter depending on the volume and filter (root) area and exposure of the plant filter.
A good compliment in a small pond would be a Hydro Pond Filter . The Hydro Pond IV can be connected to your Pump as a pre filter (these are rated up to a 1500 gallon pond).
A UV Sterilizer can be added "in line" would further compliment this system & is highly recommended (best if used at slower flow rate and it is important to change the UV Bulb every 6 months in warm climates; 12 months in cool climates).

Another complimentary filter for a smaller pond (under 500 gallons) would be the Via Aqua BF2000 pump filter combination.
For larger ponds complimentary filters could include DIY water fall filters utilizing volcanic rock, plastic mesh, and poly pads or multiples of filters such as Pressurized filters (which are among the most efficient in design in my experience).
A good pump for medium to larger ponds that can run multiple features (including your Veggie/Bog Filter) would be the Via Aqua 18000 Multi-Duty, which is a hard pump to beat when one considers performance, reliability, design, and price.

As for the pump, I recommend the Via Aqua Pumps as they are a good combination of state of the art impellers coupled with proven electromagnet motors and value.

FOR MY FULL POND ARTICLE, please visit this link:
“A CLEAR POND, PROPER POND FILTRATION, CLEANING & MORE (even pond scarecrows for predatory birds)”

For Replacement UV-C Bulbs/Lamps to keep your Pond Sterilizer/Clarifier at peak performance:

UV Bulbs; For Ponds & more
I recommend changing your UV-C Bulb every six months for warmer climates (So. Calif., etc.) and once per year in cooler climates.

Labels: Aquarium Pond Answers Directory, Bog Filter, Bog Plant Filter, Clear Pond, Plant Filter, Pond Filter, Veggie Filter, Water Iris