Natural Ponds: Common Problems and Treatments

Common Problems

  • Algae growth and other undesirable aquatic plants
  • Excessive bio matter (leaves, branches, dead vegetation)
  • Lack of water movement


Generally there are cattail family plants (Iris, lilies, rush & grasses) which are very healthful, but also aggressive growers and require pruning to keep them balanced.

Duckweed a type of floating plant – will cover a pond quickly generally due to lack of water movement, and will sit all growing season long.
Algae, there are generally two types (peas soup or string) and they blooms due to excessive nutrients and strong sun light.
Most treatments for aquatics require special State approval and not treatable as in other states do to CT regulations.


Bio-Mass is all the fallen leaves, branches, trees and dead aquatic plant growth (organics) from previous years. The slow decay creates excessive nutrients which is a “food” for the algae and other “plants” you don’t want. The massive build up of this material year after year reduces the depth of a pond, which further decreases the health of it.


Movement of the ponds water is a natural purging and cleansing of the system in both surface from a stream inlet and opposite end overflow and in good depth, the bottom will move/turn over. This is very healthful for the system.

Suggestions and Solutions

1. Move the water, move the water!

In the majority of the cases my shrst recommendation would be bottom aeration. This is a green solution, with a compressor on shore and a diffuser at the bottom bubbling the water, increasing in effectiveness the deeper the pond.
When shallow depths are the case, bottom aeration is not the recommendation. Instead use a water pump. This can be a fountain with a spray into the sky and splash back down to the pond, generally more decorative then functional, but aeration is added this way and lights can be added if desired.
The next alternative for achieving maximum water movement would be horizontal circulators, moving large volumes of water across the surface of the pond. This is a great option as it usually requires only 12-18” of water and can cover a large area of the pond to aid with the bio-mass decomposing.

2. Break down the bio mass

This is best accomplished with water movement and beneficial bacteria. The bacteria will aid in breaking down the organic masses that have built up over years of neglect and have resulted in the shallowness of the pond which once had good depths. Adding the bacterial sure beats having a pond dredged based on cost, but it is NOT an immediate fix. Adding the bacteria should be done monthly during the growing season, usually April through October in this area.

3. Add plants

Attractive aquatic plants provide shade. Shade mediates water temperature as a results, limits the amount of excess nutrients. Attractive plantings in the pond offer competitive higher level plant life to bloom in the pond. When planted on a floating island the root structures can grow rapidly utilizing the excess nutrients discussed above. In addition the islands offer shade to mediate the temperature holding un-wanted plant growth to a minimum. Plus the island can be taken ashore in the fall and the excessive bio-mass can be pruned easily and REMOVED from the pond before decaying there.

4. Regular Maintenance

Pruning and basic cleaning of the pond is a basic labor skill that can best be hired through your landscaper. Although specialized pond service contracts are available at Cooper’s.


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