> Hi Folks,
>
> I am currently trying to grow aquatic plants in my tanks, using CO2
> injection and PMDD fertilizer. Is anybody else doing the same?
> I seem to be having some sucess, but I am concerned about the level of
> copper that I am introducing with the trace element mix.
> I am using Manutech trace element mix, according to the box this
> contains 1.25% Cu, rather higher than I would have liked.
I don't know how to evaluate that amount. You would have to give the
other transition metal concentrations to decide if it is "excessive."
> Assuming zero usage by the plants, at the rate that I am adding Cu,
> with 25% weekly water changes I calculate that the long term
> cumulative level will be 0.0133 ppm.
Plants will use a non-zero amount of copper.
> Is this excessive?
No, especially since the level in the tank is probably lower than that.
> I must be very close to that level now, and the fish, freshwater
> shrimp, snails,and plants all seem happy.
Yeah well, there you go.
Craig