How long before the efforts sea watch is taking to clear out the bacteria will be seen. My vacation is in 2 weeks. I take coumadin and my son has a suppressed immune system. Century 21 New Horizons told me if I cancel I run the risk of losing my already paid in full vacation if the unit is not re rented and 16% if they do rent it. Either way I am out money. Will it be safe in 2 weeks.