very nicely put. Ingrid

On Mon, 1 Dec 2008 09:53:02 EST, DavidM wrote:
Perhaps it is again time to question the list on the difference between
a veggie filter and a bog.

So, to clarify;

*Veggie filter*
- High levels of dissolved nutrient and mineral (excrement from pond
organisms and decomposing plants).
- Alkaline pH due to dissolved nutrient or pond keeper intervention.
- No or little soil (dirt) to encourage root growth and removal of
nutrients from water.
- Constant flow of pond water through or between plants.
- Probably topped up with tap water (water hardness not a major factor)

*Bog garden*
- Very low (approaching zero) nutrient and mineral concentrations. In
nature the plants do not decompose, they just die and become part of the
anaerobic peat bed.
- Acidic pH due to peat composition and anaerobic conditions.
- Dead peat(sphagnum moss) based environment with live moss on the surface.
- NO soil (must not contain nutrient rich decomposed organic matter).
- Very low water flow rate. Mostly still and saturated, or close to
water table in nature.
- Must only use rain water or water with no dissolved minerals and
carbonates.

Since both are heavily planted, can't one use either or both?
Can a bog serve as a veggie filter?

No, for the reasons above. Most importantly, the pH will be put out.
Either the bog will drive it down to acidic levels and cause the fish to
die, or the pond will drive it up and cause the bog plants to die.

How is dirt used in either?

Dirt (soil) is a mixture of decomposed organic matter with different
amounts of sand or stone depending on the environment. Bogs contain no
soil, only dead anaerobic sphagnum moss (sold as peat in garden centers)
covered in a layer of live sphagnum moss.

I don't use any soil in my veggie filter, just bare rooted plants.

Can they use the same plants?

Absolutely not, bog plants will die in a veggie filter and visa versa.

Is the difference merely water depth?

No. My veggie filter is a 6" deep trough with constantly flowing water.
The plants (water cress, mint and iris) just float in there. My bog
garden is 18" deep and full of peat (dead sphagnum moss) and sand. It is
saturated with rain water to about 2" below the surface.