Geosmin is one 'bad' flavor in the water produced from algae usually Cyabnobacteria (bluegreens) and some bacteria. Geosmin type chemicals are what usually flavor fish fillets and water. Web search geosmin.
http://www.microbac.com/uploads/Technical%20Articles/pdf/Geosmin%20and%20MIB%201.pdfFromWiki: The human nose is extremely sensitive to geosmin and is able to detect it at concentrations as low as 5 parts per trillion.
Geosmin is responsible for the muddy smell in many commercially important freshwater fish such as carp and catfish. Geosmin combines with 2-methylisoborneol, which concentrates in the fatty skin and dark muscle tissues. Geosmin breaks down in acid conditions; hence, vinegar and other acidic ingredients are used in fish recipes to help reduce the muddy flavor.[9]
I have good luck catching tilapia with hook and line by firstly regularly feeding the tipalia pellets. Secongly you should fish for tilapia before the water turns cool and definitely above 65F when tilapia are still active. When you want to catch the tilapia use an artificial pellet such as Stubby Steve's or Berkley Power Bait as bait on a small hook under a small bobber near or at the time when you are usually feeding pellets. Use a small light wire hook such as Aberdeen #6.
