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Re: [APD] Copper poisoning in plants




I tried to set up a pond in a new Hospital Building here in Darwin NT, Oz.
The new pipes were all copper.   The water lilies and fish all died after a
few weeks so I started to test for a few different things.   The copper
levels were over 3 ppm so I looked up the safe drinking levels for humans.
It was about 2 ppm.   We reported the high copper levels in the water as a
problem for both the pond and the patients.   They Hospital Admin filled in
the pond and put a nice pattern in the gravel.   I expect the copper levels
would have come down after the copper pipes aged.

I have also tried to kill snails without killing plants in my plant
production ponds.   Some plants are more sensitive to copper than others.
Copper toxicity changes with pH.   Copper can be removed from water via foam
fractionation (protein skimming).     Yes it does work in fresh water but
not as efficiently as salt water.  I have a skimmer on my plant ponds and I
use it as an indicator when to siphon sludge off the bottom.   It foams when
the organic compound levels in the water start to get high.   When I used
low levels of copper sulphate to treat snails the foam was blue so I turned
it off during that treatment.

If you obtained a small swimming pool pump, set it up on a 1000 litre tub
then forced the water through a 25mm venturi into a 2 meter high  150 mm
wide protein skimmer I am sure you could remove the majority of copper from
your water.     You could then use that water for water changes.   Mazzei
make big venturis.   http://www.mazzei.net   I have seen all manner of
things lifted out of the water using skimmers, plastic filings, algae,
chemicals used to treat disease in fish.

If you want photos of fresh water skimmer at work email me off the list.


Cheers
Dave






On 12/5/06 4:23 AM, "Michael Teesdale" <zapins at gmail_com> wrote:

> I was wondering whether excess copper in the water column will cause
> problems with rotalla species/sagiteria/ludwigia. What are copper poisoning
> symptoms?
> 
> My rotallas have no new growth when placed in the suspect water. They do not
> grow, and simply turn black and then rot away. The ludwigias have trouble
> rooting now (as did the stellata) as the root area just turns black and dies
> up towards the leaves. In addition, my shrimp have been dying off after
> water changes, and i see yellowing on some of the sagiteria leaves/other
> plant parts. The yellowing is not due to nitrates/iron/sulfate since i know
> exactly how much is in the tank, and it is far above deficiency levels.
> 
> There is a sign in one of the buildings next to my tank that warns people
> "This water has high copper levels, but the levels are not toxic to humans."
> I mean it all makes sense, my shrimp are dying, some of the sensitive plants
> are dying, sagitteria, ludwigia, wachilli and others still are showing
> iron<http://www.aquaticplantcentral.com/forumapc/autolink.php?id=35&script=sho
> wthread&forumid=10>deficiency
> symptoms.
> 
> I did a bit of research on Cu symptoms, and one thing that high copper does
> is limit the uptake of
> iron<http://www.aquaticplantcentral.com/forumapc/autolink.php?id=35&script=sho
> wthread&forumid=10>,
> so 
> iron<http://www.aquaticplantcentral.com/forumapc/autolink.php?id=35&script=sho
> wthread&forumid=10>deficiency
> symptoms show up.
> 
> What do you think i should do? Also what are the levels of copper that are
> toxic to plants? I bought a test kit thats accurate to 0.01 mg/L that should
> be comming soon. Hopefully that will be sensitive enough to tell what is
> going on. In addition, i will be testing the water at the lab for copper, so
> i will probably be able to obtain a much more accurate reading.
> _______________________________________________
> Aquatic-Plants mailing list
> Aquatic-Plants at actwin_com
> http://www.actwin.com/mailman/listinfo/aquatic-plants

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