This formula's own materials state this directly, and repeat it in more than one place: every SodaTide order is a one-time purchase, with no automatic recurring billing.
This formula's own materials mention "no subscription" both in the hero section and in a dedicated FAQ answer — worth reading that repetition as a direct, deliberate assurance rather than fine print.
Read the full checkout page carefully before entering payment details, and confirm no recurring-billing checkbox is pre-selected, even though this formula's own materials describe the purchase as one-time.