I have well water... When I run the water for a significant amount of time it will turn brown and stay brown for a few days... Why does this happen?? Please help...

If this is happening ONLY at the hot water then suspect the anode rod to be an issue here... water heater may be on its way out.

If this is a whole house issue (hot and cold water) then you may have an iron bacteria issue... may need to "shock the well" (bleach the well and house pipes) or contact a local filtration company to take samples and make recommendations for you.

No rhyme or reason here as to why this happens... could be low levels of water letting bacteria proliferate... could be a shift in ground water flow that bisects an area high in iron bacterium, etc... ;)

Back to you...

Mark