Unless you clean it like a champ, not sure how sterile your bottle is...
I've got bad news for you - look up into antacids and how they block acid barrier. Every other one uses them.
I am not into cleaning frenzy, quite the opposite, but water should be kept as sterile as possible IMO.
Ecolab oasis multiquat is what I buy, it’s like $80-100 but the dilution ratio means you are unlikely to run out.