Potassium is the #1 deficient nutrient mineral in aquaponics and must be added to insure proper growth of your plants and for them to give you produce with the proper amounts of potassium in them for you to consume.
The next part of MKP is phosphate. Phosphate is very much needed for the production of seeds, which in turn produces larger fruits.
For more on both minerals, please see our deficiency guides.
We offer it in both 16 ounce and 64 ounce packs with free shipping of course.