Dono -- my thinking is that even though I might not need the alum is that it can't hurt right? What is the EC you are referring to is that a result of the alum or something else?

Esshup -- I understand what you mean with the stocking size. Now the pond I am referring to was stocked with HCBG and has not been managed an is over crowded. The fish are not growing the way they should be the pond is 3 yrs old an the fish average only about 6". The owner was wanting me to take several hundred from it would this be a good idea and how many that size would I need for my pond? I'm all about free plus we would be able to fish for them right now!!