Iron in fill water?

[purptiger]

Today I tested my fill water which is a well. My #'s were

ph 7.2
ta 180
ch 180
75 deg.

I tested the copper and iron with a lamotte colorq kit and when I followed the test directions the iron read lo same with copper. So I tried again and this time I shook the test tube and the result was .1. I do have some yellowish tan stains in shallow end of the pool. So I am wondering if I could have iron. Before using a swg I never noticed these types of stains. What do you experts think?

 

[JasonLion]

Tan stains could be iron or they could be organic staining. If you place a vitamin C tablet on the stain for 30 seconds and it goes away or lightens significantly then it is iron.