While in the process of seining and killing my CNBG pond out, I looked at several options for the final cleansing of the pond. It was imperative that no fish be left, whether they were preferred or not. Rotenone was not a viable option for me because of the need for an applicators license to purchase, the cost, and my unfamiliarity with the product.
After searching the various Pond Boss threads relating to this, and talking to Todd Overton who's providing my new stocking, I decided that hydrated lime was the way to go.
First thing I did was drain the 1/5 acre pond until I could see the backs of the fish.
After this we seined the pond to get all the fish out that we would relocate. This was by far the most difficult part with 18" of silt before we hit the clay bottom. When we finished, we wound up with an approximately 40X20 foot area, 6-8" deep, to lime.
Todd had recommended 100 pounds for a 20X20 area 2" foot deep, so I had slightly less water volume than we had accounted for. At $7 a 50 pound bad at the local box store, I spent less than $15 total. I will add that I found hydrated lime in the concrete section, and it was not the same as the lime in the garden center.
I had originally thought about using my pump to create a slurry that I would spray over the pond, but ultimately decided to do a drop and spread method. Both 50 pond bags were placed in the remaining water and spread with a garden rake until the all muddy water was evenly colored by the lime.
Within a hour, the water started to clear, and the remaining fish were struggling. Also, the pond's PH was unreadable by my test strips. It blew the numbers off the chart. After 3 hours there were was no activity and the pond was effectively cleansed. It's hard to see, but the extremely turbid water was crystal clear from the lime application.
2 hours later we started the refill. It should be at near pool level by noon today, and the 100 pounds of lime easily absorbed in the full 1/5 acre pond. As a side note, before I added the lime, my PH was at 6.8 which is the natural level for both this pond and my big puddle. Monday, I'll recheck the PH before continuing.
My do it yourself seine and lime rig.
When handling the lime, I wore a cheap rain coat, rubber gloves, hepa mask, and goggles. This might have been overkill but I've seen hydrated lime burns in ER's before, and they're not a pretty sight. All family members were kept upwind also.
So, any comments on errors or better suggestions are welcomed, but it will be a while before I seine any more ponds. It's a lot more work than I had anticipated because of the muck, but the hydrated lime was a cheap and very effective method for cleansing this one.