If you have a large pond and are suffering from an ongoing algae bloom, and particularly if you've been using beneficial bacteria to lower nutrients that feed it, yet the algae stubbornly hangs on, you may want to target it's primary support, called phosphates, a bit more specifically.
Here's the bottom line. You can't get an algae bloom without an available source of phosphates in a pond.
Often enough, a good quality beneficial pond bacteria will help with all the primary nutrients that stimulate algae growth including phosphates, but sometimes they may not be enough to bring phosphate levels down to an insignificant level.
Even relatively low levels of phosphate (30 ppb) can cause algae to grow and the higher that number goes, the more aggressive the algae growth will be.
There are several ways you can "lock up" or bind to phosphates which make them unavailable for use by the algae. One of the common chemicals is called Alum or Aluminum Sulphate. Alum works quite well on phosphates but it can also affect the pH of the water and if this changes dramatically enough, it could be dangerous for fish. Its for this reason that Alum instructions indicate a specific pH range to use the product safely.
Our natural phosphate binder contains no chemicals and although it works a bit more slowly than Alum, it is very safe for fish and other wildlife in your pond.
Dosage rates can vary widely based on the level of phosphates in your pond. The suggested dose is 3 to 5 pounds per acre foot of water. Repeated dosages may be applied as required to bring available phosphate levels down.