CH Test Questions/ CH Rising

[Gracy101]

Thank you for your quick response. Went out and did as suggested (11:30 am) - numbers are as follows:

CL 6.0 TC 6.0 Ph 7.6 Alk 80
Air Temp 82 Pool Temp 82

CH 525 again - still had the floating particles in the end result. I want to say the change in color was more easily discernible but not really by much.
As for the brown stains - the vitamin C took them away real quick.

So - I'm not sure if I get this but it looks like:

1) Brown stains are iron - which vitamin C will take away obviously. But can you only treat the individual spots or can you treat the pool in general to remove them and prevent them in the future? Why is it happening in the first place?

2) The particles I see are caused by magnesium - which is related to my elevated calcium hardness levels. And the iron stains are also a byproduct of the CH? Any ideas why this is happening in the last few months...

3) Do I need to test for metals then - how/where do you do that? Please, please don't say the pool store...yikes!

I don't just want to fix it I want to know why it's happening so I can prevent it if possible. Thanks again.

Gracy