I appreciate that you had the right intentions here
@alvarengadaniel8 and I'm not trying to be negative here or try to single you out, because this happens a lot across the country.
There are a few unfortunate problems with this type of activity:
1) Petco now made money on the fish rather than letting it die, meaning they're going to purchase more, and the cycle continues. If they don't show losses, they're going to continue selling.
2) Kenny can't take fish randomly without notice because his quarantine process takes 2+ weeks and if he isn't in an in-between cycle, he'd have to start over, meaning more stress and losses on having the current fish having to deal with copper or other meds longer.
3) You can instead complain to the manager and or corporate at Petco saying that they aren't keeping their fish properly. Also you can leave negative reviews on Google reviews or Yelp with pictures of their sick or mistreated fish as that will further keep people away from their location.
Our club goal is of course the ethical treatment of marine animals and the best way we can support that is by spending money on our local fish store partners that do put effort into keeping their animals healthy.
Your heart is definitely in the right place though!