"Brian Watson" wrote in message...
I have a two-level triangular pond (approx 20' each side overall) which has
become very silted up with dust and muck blown in through the winter.
I have been quite diligent in removing leaves: it's the fine particle
stuff
that is my problem.
The water is clear (I have a sturdy pump/filter which runs 8 hours a day)
but a lot of the muck that is building up on the bottom is not within the
pump's collection range.
Currently, as well as a good stocking of plants, I have frogs, tadpoles
and
at least two species of newt co-existing quite happily with visiting
dragonflies etc etc.

All very "in balance" but the muck level is rising and I do need to get
quite a bit of it out with minimal impact on my wildlife.

Care to explain, if everything is good, why you feel
you need to get the muck out?

Can you recommend a suction device with an effective front-end filter that
would shlurp up the muck but leave the tadpoles and other wildlife
unaffected?

A couple years ago, I did a very "redneck" * solution.
I used a 16 gallon "wet/dry" vacume.
Put nozzle on bottom, best to have someone else
turn it on so you can be moving the intake sweep along
bottom (yeah!! things happen fast!), until 'bucket'
is about half full.
Yeah, any fish etc. stupid enough to out of silly
couriosity go swim over to check out this
strange 'sweep/nozzle' will feel they have been
VERY rudely treated. Very rapidly transported
from pond, through 'sweep' & large hose
into a bucket 1/2 full of very mucky water.
But, really nothing seriously injurious.
(since motor & propeller & filter are after
the holding bucket).

Remove lid (with motor & filter) and allow
to 'decant' (and you can sift through for any
good things you wish to rescue & return to pond.)
for a day. When settled you can return the top
clear water, & put ~3 gallons of muck in garden.

* "redneck" a USA term,
often for crude, but often effective enough solutions.
Below is only somewhat correct
http://en.wikipedia.org/wiki/Redneck
Go ahead and google, & google images
"you might be a redneck if"