There is no clear cut answer to this question because there are so many variables involved.
However, we can offer some guidelines based on our experience.
Changes will happen faster in warmer water, with sufficient aeration & mixing.
For minor problems with relatively new ponds you should start seeing changes in a few weeks to a month.
Older ponds that have taken many years to develop problems will take longer to fix. It is not uncommon to require a season or more of treatments with a natural product before you start to see results.
The key is getting the nutrient loading out of the water. This usually involves addressing the sludge layer at the bottom of the pond and cleaning the water column itself with enzymes.
Plenty of dissolved oxygen (good aeration) is a requirement for all natural products to work as safely & effectively as possible.