If this post isn't a joke:

1. Don't suddenly add anything to a guinea pig's (sole) water bottle. That includes supplements. Guinea pigs are incredibly picky and will quite literally thirst to death if something seems "off" with their water. There are reports of owners adding supplements to water and checking in later only to find dead guinea pigs.

2. Your real fuck-up is buying a single (!!!) guinea pig without doing basic research, I'm assuming.

I'm guessing/hoping this is a troll post, so I'd rather not waste more time writing, sorry.