Don't trust your pH reading taken while the pool had high chlorine. it will typically read falsely high. Wait until the chlorine drops below 5ppm and then recheck pH.

Why did you add the metal control initially. Do you think you have metals in the fill water? Why don't you do a bucket test to check for metals.

When testing for metals, you'll need the following:

(2) white 5 gallon buckets.
A 1 gallon or 1/2 gallon clean milk jug or orange juice container (to measure with) OR
A household scale accurate to within 1 lb.
A *fresh* jug (96 oz or 1 gallon) of plain 6% household bleach.
A box of 20 Mule Team borax.
An OTO testkit, like the Taylor 1000 or the HTH 6-way drops kit. (Test kit info page)
Lids or towels you can use to cover the buckets.
A plastic or stainless steel tablespoon measure
A plastic or stainless steel 1/4 cup measure
A clean household long-handled stainless or plastic cooking spoon.

To carry out the test:

Use the gallon or half gallon measure to collect pool water.
Fill the first white bucket with 4 gallons of POOL water.
(Measure by adding 4 measured gallons OR by adding 33 lbs of water to the buckets)
Fill the second white bucket with 4 gallons of FILL water, from whatever source is used to fill the pool.
To each bucket, add 1/2 cup of bleach & mix (~80 gal bleach /10K gal pool -- 480 ppm)
Mix completely with the spoon
Wait 15 minutes, and note any color change.
To each bucket, add 1/2 cup of borax,
Mix with the spoon till dissolved completely
Cover with lid or towel.
After 24 hours, inspect. Note clarity, color and sediment, if any visible
After 24 *more* hours, inspect. Note clarity, color and sediment, if any visible
Test both buckets for chlorine levels with OTO. You should not get a 'normal' reading, but report resultant color.
Report results.
Recover the buckets, and wait 3 days, and check again.