In hot climates the water system will get funky in just a short time. If I was you, I would drain the hot water tank and low point drains and sanitize the system with bleach.
In the future, if you are not going to use the trailer for a week, drain everything, every time.
2017 Salem Villa Estate 395RET-
2011 Coachmen Freedom Express 295RLDS- Sold
2015 F-250 FX4