Hi, We just pulled our Chaparral jet boat 2016 223 VR for the winter but need help with 2 issues: 1. We want to put the additive in the gas tank before storage but can't find the size of the tank in order to calculate the correct amount. 2. We are in fresh water on Lake Keowee, SC. The boat was at a dock but not in a lift all summer. What should we use to clean the bottom of the boat? Thank you for any advice!