I have a 25'x25'x24" pond with a 60'x2' stream. 40% covered in plants. 4-6
6 inch goldfish, and some baby goldfish, a few frogs. External self priming
pump and no skimmer or biological filter. No stones on the bottom of the
large pond. The water recirculates up to a 3'x3'x12" pool with stone in it.
The water then cascades over a 36" fall into the stream. The pond is
relatively clear.

1. Do I need to install an expensive man made biological filter? If so,
can I use small stones in the smaller pond to act as surface area for
bacteria?

2. Do I need to clean the bottom of the main pond on a yearly basis? If so,
why? Can I do damage to the natural system by stirring it all up?

3. Evaporation? Given the dimensions above and our summer temps in the
60's to 70's, I have noticed that the level of the large pond area has a
loss of about 1/8" for two days. We've had no rain. Given the surface area
of my larger pond area and the length and width of the stream, is there any
evaporation that I could actually measure?

Thanks for your help.

--
Steve Shapson
Southern Wisconsin

We don't have a man made bio filter either, or a skimmer.
We have a undergravel filter in our actual pond. The water is also filtered
through rocks on both levels of the waterfall .What we do is use a shop vac to
clean the rocks on both levels of the waterfall. We have a drain on the
outside of the pond that we use to clean the pond. We stir up the rocks so
that stuff floats to the top and turn the drain on. As far as evaporation,
thats just a given. I myself feel that the pond should be cleaned really good
every fall and every spring. Now others may have different ideas.









Jan
"Our Pond" Page
http://hometown.aol.com/pinkpggy/index.html