Open the radiator (when it's cold of course) and pour coolant in until it won't take any more. Run the motor until it is warm and the fan clicks on with the cap open. Squeeze the hoses to remove any bubbles from the system and put the cap on. This will remove all air from the system and will prevent the overheating Hondas are prone to. The overflow tank is pretty useless as it just allows the coolant extra room to move during the expansion/contraction process when it is heated. Then you can fill the tank to the max line. I wouldn't worry so much about the reservoir tank as I would about bubbles in the system after the install of that hose.