Well I don't know when you throw in "Ethanol", alcohol absorbs water and you are in Florida. I am SC and my MH is parked 30' from a big lake. I do not fill my tank but I do treat it with Sta-Bil "Marine", this is made to treat Ethanol. I do not want 75 gallons of 4 month old Ethanol in my tank! I also do the same for my boats, no problem yet, however the boats have large (more than a quart) water separater fuel filters on them.
Sunny South Carolina
2004 Pace Arrow 37-C WH W-22