Aquatic Pollution and Coastal Management

Unit 3 : Agricultural wastes and eutrophication

3.13.2.2.Phosphorus and Potassium
Phosphorus and potassium also occur in more/less usable 'forms'; like nitrogen, they rarely have to be augmented in a 'normal' set-up. Enough comes into a system by way of tap and fish food sources to supply all but the most "boosted" plant arrangements.

In highly acidic conditions phosphate "fixing" can be a problem with this material becoming insoluble, hence the use of some carbonaceous material as substrate. Too much phosphorus as phosphate (less than 1ppm) results in algal blooms.

Potassium shortage shows up in older leaves as small spots and holes, resulting in leaf loss.