How many are needed for a 2,000 gallon pond?

For a 2,000 gallon water garden pond we typically recommend using 2 bags of our 300 pack of bio balls. The bio balls will handle the bio-load of a typical stocked pond. With this said there are variables which effect how heavy a bio-load is in a pond including: how many fish, their size, how often they are fed, and so on. The only way to know if you have enough bio balls is to test your water for ammonia or nitrites. If you detect ammonia or nitrite levels in your pond water (not caused from overfeeding or a dead fish) add more bio balls.