My friend and her family went on a week long cruise. Her husband set up an automatic feeder for the turtle (adult - BIG turtle, BIG tank). She said to check on him every other day or so. I checked Sunday after she left, all looked OK. I checked today (Tues) which is two days after she left. The house STUNK when I walked in. I go straight to turtle, and water is about black. The autofeeder was on overdrive apparantly, it is about empty. The feeder is about the size of my fist to give an idea of how much food was dumped in there. The tank, I dunno at least 3 feet long if I had to guess.
I took it off (it only had about a T of food left in it). I have NO idea how to care for turtle water. They have a well. I don't know if she uses the well water or does bottled water. If bottled water, what kind? Obviously in my knowledge I am only equipped to do a partial water change, should I do this? Would the filter clean out the water if I just left it alone or do I need to do partial water change ASAP?
I apologize if this is the wrong place to post this is urgent IMO and I have NO idea how to care for a big turtle and it's big aquarium. Please advise in layman terms. I have NO way to contact her.

