Hi Jan,

Our pond system has 3K gallons in the main pond and 1K gallons in the
berm ponds and barrels. The pond has about 10 koi, full sized, and
about the same number of goldfish. The berm plants do a great job of
handling the muck...growth like crazy and clear water. We have not done
any regular water changes. The toilet valve does replace the
evaporation on a regular basis...MS is very hot. The koi don't seem to
have suffetred any particular problems from the lack of changes. They
have grown like weeds and are 20 to 28". The ratio of koi per gallon is
pretty good. That may help.

Jim

~ jan JJsPond.us wrote:
Our toilet valve refills as we get evaporation. We drain the barrels
and the berm ponds annually to dump the muck form the pond. That does
actually mean turning over 1000 of 4000 gakllons. That is an annual 25%
change over...staged. We have monitored the water chemistry and it does
not seem affected by the low change rate. My observation is that the
pond does a good bit of topping up, which should be concentrating the
minerals.

Jim


Is this a water garden w/koi?

Your last sentence confuses me, as the reason it is recommended 10%/week is
to keep heavy minerals, pheromones and other pollutants (that most
hobbyists can't test for) diluted and to add necessary minerals, vital for
the fish.

If a koi only pond, they usually need to do them for the nitrate build up
also.... something we rarely have to worry about in a water garden plus
koi. ~ jan