Well, you've got the good test kit, so we can eliminate measurement as a possible source of error for your alkalinity. That's a lot of lime for so little return. I guess my question would be whether or not you distributed it uniformly around the pond. In order for the lime to be most effective, it's supposed to cover the entire pond bottom. How was the lime applied?
I have never used hydrated lime simply because I've never read a reliable source that recommends using it. Therefore, I can't tell you much of anything about it except that I personally wouldn't risk it.
Keep in mind that it takes a while at lower temps for a bloom to establish. Even with an alkalinity of 16, I would expect some bloom response. I find that in my area, consistent water temps of 70-75 degrees are needed for a bloom to establish.
One last thing. Be careful. Don't do something that may kill all your fish in an attempt to get just a little better fishing.
