For a 30-40 year old pond (with 30-40 years of organic sediments built up), I'd budget the aerator first too. Protect those good fish you've got.

Spend a little money (as little as $25) for a seine. You can get pretty good data from a DIY survey - seine/net results, creel records, and observations while hand feeding (the other bonus besides saving the auto-feeder cost is YOU ARE THERE). Not as good or as quick as a professional survey, but good data over the course of time.


"Live like you'll die tomorrow, but manage your grass like you'll live forever."
-S. M. Stirling
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