My Oneida Black Eagle sits at 30lbs Mission Menace at 32lbs. These are actually cranked up a bit for colder harder fleshed fish. In the summer i shoot about 26lbs with my Oneida.
I heard some people saying in like 3 to 4 foot water the need their bows set at 55 60 pounds in order to penetrate the fish.
Naa... I shot carp last year in 3ft of water at 26lbs.... Its all about having a tuned bow with arrows that enter the water so straight they dont even make a splash. I shoot a Muzzy XD spincast reel with small diameter line which results in better arrow flight and less drag. The highest weight ive shot recently was 45lbs, because i was shooting at big commons and 60-70lb grass carp in 4-6ft of crystal clear water. I wanted the weight to poke through the big ones.
My Oneida is at 28lbs. I've shot 30+lb bigheads in six feet of water with it. Arrow flight is critical at lower poundage... but it's easy to get fish arrows to fly straight. What kind of bow will you be using? You can shoot it at 50lbs but if you're shooting in shallow water you'll spend a lot more time fighting mud and roots with the over penetration.