For

most ponds, gypsum application

rates will range from about 1,000

to 2,000 pounds per acre (Fig. 4).

In hard-water ponds (calcium

hardness greater than 50 mg/L),

the water is nearly saturated with

calcium and gypsum may be ineffective.

In that situation, alum will

be the only effective coagulant.

All the coagulants mentioned can

remove phosphorus from water.

As phosphorus is an essential

plant nutrient, it may be necessary

to fertilize the pond after treating

it for turbidity. On occasion, phytoplankton

and clay can mutually

coagulate, so fertilizing to start a

phytoplankton bloom may also

clear water of suspended clay particles.



Lime = better water quality and fertility when needed. Read this.

http://srac.tamu.edu/tmppdfs/144249-464f...f9518a72c2f7d5d