[Noah930]

Hot water --> no silt
Cold water --> lots of silt
Warm water --> medium amount of silt

Furthermore, this is only happening in the three bathtubs and the shower. The sinks work fine...so far.

It's fine, but particulate. Like very fine beach sand.

This house is a rental. We've lived here for a year-and-a-half with no water problems until recently. Water heater leaked. Plumbers (surly Russian type) came out and replaced it. We've had some water pressure and temperature issues since then; can't take a shower and run the dishwasher or clothes washer at the same time, for example. But, suddenly, this evening while running a bath for the little girl, this started happening. Fortunately, I had washed everything but her hair, by that time.