Treating your Natural Pond for Algae
If you have a natural (soil based and sided) pond, you have a lot of nutrients constantly coming into the water from that soil. This makes controlling the algae in the water very difficult although not impossible.
Instead of an instant fix, we have successfully worked with natural ponds in the past to produce a hydroponics area of plants that over a period of time will removed the excess nutrients from the water and therefore control your algae problems.
Depending on the size of your pond you would have to adjust the amounts accordingly, for a pond of approximately one half acre you would need:
1 large truck load of gravel (acid reacting rock preferably - do not use alkaline reacting) tipped into the pond.
Level this out so you are creating a beach effect with the stone about 6 inches under the water surface. The stone should be at least 12 inches in thickness to the soil.
Plant the stone area with water plants, the best working ones are listed below.
This will make the plants feed from the water, not the soil and you will therefore start to create a hydroponics area. The amount of plants you can purchase decides on how fast this will work. The more plants the more nutrients are being absorbed.
This procedure works through the winters as well as the summers and the plants listed below are extremely frost hardy.
Plants that work in hydroponics areas very successfully
Iris pseudacorus (Yellow Flag Iris) – The best plant to use in this circumstance, the downside is that it is on the US Government invasive plant list; there are also around 15 varieties of this plant including some that are infertile.
Iris laevigata (Japanese Water Iris) – this is a smaller plant than the Iris pseudacorus and not so voracious at feeding. It also comes in around 14 varieties but will be slower growing.
Mentha aquatica (Water Mint) – This plant is shorter and is very highly scented as well.
Rorippa nasturtium-aquaticum (Watercress) – This is the watercress that you can purchase at your local grocery store. When planted hydroponically the plant is very strong tasting and not suitable for table use.
