Robert Pavlis

Depending on where you live, you may not get permission to alter the stream. Check with local authorities before doing anything.

Lets say for a minute that this is true; "anaerobic decomposition of organic matter creating an impermeable biofilm". What happens to organic matter over time? It decomposes. When that happens the seal in the pond will be gone.


This does not make any logical sense to me.

No. Without enough clay, you need to either bring in some clay for lining the pond, or use a liner.

sorry - I know nothing about sealing a pond with animals.

In theory a swimming pool will work just fine, but it does have one problem. In order to control algae you want to grow plants and most swimming pools are too deep for plants, and they lack the shelves usually used for plants.

One solution is to build a biological filter beside the pond which contains the plants, but they you need a pump to push the water to the filter.

Building ponds on shelf rock is not a good idea. These usually have cracks that allow water to run away. If the rocks are mostly bolder and smaller round rocks, then they should seal with clay.

Ponds without liners can be made if the clay content of your soil is high enough. A simple DIY test can give you a fairly good value for this.

The idea that pine needles are acidic is a myth. On the tree they are slightly acidic. Once they fall off, they are no longer acidic and will not change the pH of your pond.

http://www.gardenmyths.com/pine-needles-acidify-soil/

That will do quite a bit of root damage, but the tree should be able to handle it. You might want to do it in fall when the tree will get enough rain to grow new roots.

I think 5 feet deep is not much for fish, and it is shallow enough to see a lot of algae growth. Algae grows because there are too many nutrients in the water, from fish, leaves, and ducks, and too much light getting into the water. When ducks remove the plants they remove the natural water purifier, resulting in too much nutrients.