100 buscks in Vietnam, I think it's a lot. Matter of fact, can fetch me a 4 star villa here in Malaysia. Brown water is quite normal actually. How i deal with it? Everytime when i checked in a guesthouse/room, i usually will blast the water until its clear. It usually rusts in the piping system domestically within that property, and a couple of minutes run will clear them off.
Theres this one time many years ago, i took a long drive to the northen side of west coast, checked in a hotel and the moment i lodged myself on the bed, the bed rack broken into half 😅 when i requested a change, the maintenance guy had to hold on so hard whilst leading us to a new room, before my door fully closed, i can hear him burst out laughter. I got that rotfflmfao came from him 😅
I hadn't thought to just let the water run for a while but to be fair we did fill up a lot of the tub and it was still brown. Perhaps the boiler or wherever the hot water is stored is so badly rusted that it just stays that way. I dunno, I wasn't going to take a bath in a tropical country anyway.