See if I have this about right:

From Lum's numbers,

150ml X 1%(1g CuSO4*5H2O/100ml) in 1,000gal

1.5g in 1,000gal

1.5g / 3800liters

..395g / 1000liters

..395g / 1,000,000g

..395ppm CuSO4*5H2O

Times .25, as you pointed out, for actual wt. Cu

..395ppm x .25 Cu in CuSO4*5H2O = .1ppm Cu dose

It seems to come out as expected, with the % composition of copper
factored in.

My stock bottle of 1% copper sulfate bears my note that .75ml soln in 5
gal wine gives 0.1ppm copper. I don't like to trust my calculations any
more often than I must.
> My memory is of having a devil of a time converting between various
> measures of copper sulfate, including Margalit's. I can't remember
> why his was such a pain, but somehow it was.
>
> I'm not sure exactly what you have in mind, though. 0.05 - 0.5 ppm
> implicitly references volume, because it just means 0.05 -0.5
> mg/liter.
>
> Dave
> ************************************************** **************************
> Dave Breeden