Antibiotic Flakes with Doxycycline is a must have for the fish medicine cabinet. These antibiotic flakes are used as a broad spectrum antibiotic to treat both gram positive and gram negative bacterial disorders, including Fin and Tail Rot, Septicemia and Mouth Rot. It is commonly known that in pH at or above 8.0 that Tetracycline loses its effectiveness; however, this derivative is unaffected by pH. As this class of drug can have a negative impact on the cycle, keep a close watch on water parameters during treatment. Getting fish to ingest medication is as difficult as getting your kids to take their meds. This is why we use our flakes as a base. Fish will quickly gobble up the medication and will beg for more. Treatment: Offer as the only food for 10-14 days. Closely monitor water parameters and do water changes as necessary if nitrifying bacteria are negatively affected. Medicated flakes are made to order to ensure medication does not age sitting on our shelves and lose potency. NOTE: As with any antibiotic, once started continue for the minimum number of days to avoid bacteria becoming resistant to this medication.