Recommendation for DIY Test Kit for Metals

I had a problem with high CH a few weeks ago and while testing discovered some floating particles in my CH test results. I also had a few brown stains/smudges on my spa walls. These are apparently and indication of metals in my water. I need to determine if I have metals, specifically iron, in my pool water and how much, so I can formulate a plan of attack.

After partial drain, CH is down to 390 but there are still floating particles in the CH test results. The brown stains disappeared by rubbing them with vitamin C tablets.

Can someone recommend a test kit for metals? The pool stores in my area do not test for metals. I went to the Taylor website but I do not know the differences between the options, or actually what I'm even looking for. What I know about testing pool water I learned here so I'm sure I can learn this too:D .

Water is back in balance but I need to know what I'm up against with the metals. BTW, it's not my fill water, for sure.

Thanks - Gracy

Water #s a/o today 7:00 pm Pool is crystal clear with
CL 5.0 ALK 90 PH 7.4 CH 390 CYA 35

The most cost effective way to tell would be with the Aquachek test strips for iron and copper. Their iron test strips are just a bit over $20 for a bottle of 25. Don't know how much the copper strips are. You just need to know if they are present. You don't really need a lot of precision. The Taylor kit that tests for them is about $85. It's the K-1264 and it tests for copper and iron. LaMotte makes the EC-67 kit that tests copper and iron but I don't know the price or where you can get it.