Systems should be sized to have a min. of 1 gallon of storage per ft2 of collector area, more in hot climates.
To supply 65 to 85% of the hot water needs from solar for residential applications in Florida climates the following is recommended:
Two 10 ft2 Skylite 10-01 collectors (6'x20"), for the first person, and one Skylite 10-01 for each additional person.
One (or more) 10 ft2 Skylite 10-01 collector (6'x20"), can be used on a RV, boat or mobile home; or to fit the configuration of your roof.
Remember, a smaller system is still very cost effective! You can start with what your budget allows and then add collectors as you can.