I electroplated a small nut as a test, ratio hydrochloric acid / distilled water 1:5, using a 9v battery just until the nut was coated.
Positive was on the copper, the negative on a bolt, and the nut was moved around with a plastic stirrer.
I am now uncertain whether the bolt I used for the negative was stainless steel - in hindsight, it could have been. I've since learned you don't use stainless steel - It's coated in copper now (as is the nut).
I was going to keep the bath for more copper plating projects, but is it likely to be unsafe now?
If not, how do I dispose of it? I heard that using the stainless steel creates toxins/carcinogens so I am worried now.
How can I do this more safely in the future?