running low on zinc brightener

[lintmann]

I'm running low on the zinc brightener and was wondering if there is any difference in the brighteners between the new and old copy cad solutions? Can I just buy the current available brightener and use it with my old solution is what I'm getting at.

I seem to remember reading someplace that when the content of the copy cad solution was change to the current formula that a newer version of brightener was also required. I can't find this info anywhere so I'm just wondering if I can just buy some new brightener and carry on with the old solution for zinc plating or if my old solution will only be good for cad once my brightener runs out?

Thanks.

Greg