Our newer soaking tub has mud like seditment, not in any other sinks, toliets. I have filled and drained 10 times. Each time I can used towel to dry the bottom. I pick up a noticeable amount of mud like sediment. Amount seems to be consistent.

Are you on a pump or city water? Was this tub replacing another? Did it have to be repiped was a new valve? Can you give me more details? Back to you, Tom