On Sun, 10 Apr 2011 07:21:32 EDT, "Rodney Pont"
wrote:

Hi Jan,

I don't disagree that the algae uses the nitrate, that's what
plant life does, but it could be a problem if a UV unit is used to
clear the water and the dead algae isn't removed.

Nitrate and phosphates can be problem in the water here in the UK and I
thought they would be in any modern agricultural society due to runoff
from the fields. Phosphate is also added here as a lubricant for the
pumps and valves.

Patrick mentioned nitrites in one post I think, that should be zero
just the same as ammonia.

Very true, agricultural runoff, but the US hasn't been in existence as long
as the UK. :-) Patrick would have to let us know about his water source
which may be wells where he's at. I found this website, but it is by area:
http://www.wawater.com/waterquality/ccrindex.htm not city.

In, but across the state by about 4+ hours and a ferry ride, our water is
sucked mainly out of the Columbia River and has less nitrate & phosphates
than most home-made ponds. EPA allows 10mcl of nitrate, our average last
year was .9 mcl. I picked an area out of the above website near Olalla and
it showed even less. Phosphate wasn't even a concern, at least not listed.

This seems to be pretty common in the US, at least most of the US koi
people seem to recommend fresh in, fresh out on a constant basis. I know
I'm doing that because something is sucking my water out, I think all the
worms over the winter built pathways to the pond and now that I have the
stream/water fall going and the level up, its getting wicked out. Drat!
I've lifted most of the rocks along the stream, will have to do the ponds
eventually. s ~ jan
------------
Zone 7a, SE Washington State
Ponds: www.jjspond.us