Plant recommendations -- no additional fertilizer required?

[Paultergeist]

Greetings!

I am interested in trying to incorporate some plants in a bog-like filter chamber as a portion of my pond filtration circuit. The idea would be that pond water would cycle through the container, in which plants potted in a minimal amount of gravel (individual containers) -- would reside with the plant roots completely submerged. I know this has been done by others before, but I am trying to gauge how effective this method might be.

My rationale is not so much to grow the plants themselves, but rather to allow for nutrient up-take by the plants, such that algae in my pond my have a harder time surviving. Plants could be thinned as needed.

I have done this once before with water lilies, but -- ironically -- the lilies required some compost and fertilizer for decent growth. While the lilies looked great, this planting method also added nutrients to the water (via the compost and fertilizer planting medium), which then also fosters algal growth.

I realize it seems elegant to consider plants as nutrient *sumps* to draw up nitrogen/phosphorus wastes produced by fish, but I really am not clear if the inclusion of plants can result in a significant improvement of pond water quality (e.g., no green-water algae, low nitrates) on a practical level in a normally bio-filtered pond? My intention would be to use plants which did not require supplemental nutrient sources beyond that provided by fish waste, such that plant growth could be expected to pull some dissolved wastes from the water.

If you have any experience trying this -- be it success or failure -- I would like to learn of your results.

Thanks for any replies.

 

[crsublette]

Well, it does result in significant improvement in regards to low nitrates, which has been shown in the aquaponic hobby and validation can be seen through their experiments. The growing bed construction and plant's age will also impact the nutrient uptake. Browsing particular aquaponic specific forums would give you better insight. Now, in regards to the green water algae, in the aquaponic hobby, this is a bit more complicated since some folk "believe" in UV devices and some do not so to just be patient through the green water if it does occur.

I would suppose the plant selection will be dependent on the nutrient analysis of the fish waste. If the fish waste is primarily nitrogen and you are not wanting to give supplemental micro/macro-nutrients, then there is an increased reliance on terrestrial leafy green plants that is allowed minimal flowering and does not produce fruit.

Good luck to your journey!! Keep us appraised of what you learned.

 

[HTH]

To make this work well you need containers that the water can flow through. Like the sort aquaponics people use.

 

[addy1]

I have these in the bog and in the pond, never add fertilizer. Did not even fertilize the lilies this summer, they are doing great blooming like crazy.

Obediant plant
black gamecock iris
dwarf golden sweetflag
dwarf cattails
parrots feather
varigated snow flake-lily like plant needs to be planted about 14" under water surface.
Water Willow
green creeping Jenny
Marsh betony
lizard tail
pickerel weed
creeping primrose


4 leaf water clover
fuzzy 4 leaf water clover
mini spearwort
white star grass
penny wort
water mint
blue water forget me not
water iris soft pink\kirk strawn
4 left water clover variegated

 

[Paultergeist]

Thank you all for the helpful replies! Addy1, thanks also for the detailed list of plants.

 

[crsublette]

Good deal, I was hoping Addy would reply. She knows her plants. Her bog build is a fun read as well. And, maybe if you talk sweet enough and ask at the right time, she might just mail ya some plants as she did with me and they worked out very well in my watering hole.

Plants are extremely efficient at using the nutrients present and all plants are not the same. Some terrestrial plants uptake more than others and tolerance of wet feet are different and others do not work well. It all depends on the plant.

Obviously, they'll do better if they get fertilized for them to thrive, but they can still do quite well enough without the extra fertilization.

 

[adavisus]

but I really am not clear if the inclusion of plants can result in a significant improvement of pond water quality


On a well planted pond, 60% equivalent of the area will deplete the fertility of a pond in about two weeks. How that is affected by feeding the fish will be a variable, faster growing plants would help, I'd bet

Regards, andy
http://www.flickr.com/photos/21940871@N06/ http://swglist.wordpress.com/

 

[mrsclem]

I have a variety of plants bare root in window boxes on the sides of my pond. Just have a spray bar to keep them wet and they are taking over and sending roots and new growth out thru the drainage holes! Never used fertilizer.