BassDoc, welcome to the forum.
I agree with everything that Dave said, but want to add that you should remove every catfish you catch too. Once they get over around 3# they will compete directly with the LMB for food. There is a relative weight chart in the Pond Boss Archives. Print it out and get familiar how to use it. If you want to get technical, any size class of LMB that is below a relative weight of 90 to 100 should be thinned extensively if your goal is to grow trophy LMB. In an average, balanced pond, expect to remove roughly 20# of LMB per surface acre per year. To reverse a LMB stunted pond, remove 30# to 40# of LMB per surface acre per year, especially in the age class of fish that are stunted the most. Typically that will mean removing every LMB under 14" (that means even 2" fish) like Dave said.
Managing pH is important, but how you go about that is the question. pH will swing like on a bell curve from morning to night. Here's something that will help you understand how to manage pH.
http://www2.ca.uky.edu/wkrec/AlkHardness.htm
