The fact that the water is brown doesn't mean it contains iron.

If you truly pumped the water from a flowing stream, it's very, very unusual for there to be high levels of iron in surface water. It's much more likely that it's dirt.

Bacteria in well water is not going to consume significant amounts of chlorine, either.

What I'd recommend is the following:
  1. Turn your pump and filter on, and leave them on.
  2. Watch your pressure gage, and clean the filter when you see a 3 - 5# increase.
  3. Brush your pool, to help prevent stains (which might, or might not be likely to occur)
  4. Add a double dose of polyquat 60% algicide. Repeat every 24 hours.
  5. Add a single dose of liquid stain/scale agent. Do not repeat, until you've reported back here.
  6. Don't add anything else.
  7. Operate for 24 hours and see what happens.
  8. Get a testkit -- the 6-way HTH kid at Walmart is good starter.
  9. Test your pool, and report back.

The polyquat and stain-scale should help prevent problems.

Do NOT try to fix your pH, your alkalinity, your calcium or your stabilizer, yet.

Let's just avoid problems, and find out what your water has in it.

PoolDoc