The moon phases play a role in the fish activity for sure.
I read somewhere that more fish are caught during the full and new moon phases.
New moon for more of the day hunters and full moon for more of the night hunters.
I tend to agree with this, but I feel weather is also a big key on predicting what the fish may do be doing that particular day.
A few days of stable weather is usually good.
An approaching storm can have some hot fishing.
During the storm and a few days after usually poor fishing, for me anyways.
It also good to take in account, if you can, for the oxygen, light and forage levels that's present in the particular lake your on.
Too much of one or not enough of another can affect your catch rate also.
WW