Our 323 had a 10 g tank. I converted the bow water tank to a holding tank. Pearson said it is a 30 g tank, Kracor says it is 40 g. Haven't cruised yet. 2 of us staying in the marina and using marina facilities some of the time b ring the tank to 3/4 full in 7-10 days. If anyone is interested in converting a tank I'll tell you what I did. klosteratcenturyteldotcom.
Geoff