This Healthy Ponds Fountain Cleaner 25 gallon refills ship in a 4-pack; each refill is effective up to 30 days (120 day total treatment). EVERY 30 DAYS, replace the used packet with a new refill to see optimum results.
NOTE: This is an all-natural system. It may require 4-6 weeks to achieve water quality improvement. For best results, do not use this product within 30 days of chemical or algaecide applications. Recharge the dispenser every 30 days.