Startup after replanted just not going well - what is this dust on the bottom of my pool?

[gneissgirl]

Short story:
New tile, plaster and coping in February/March. Contractor was to turn over ready to swim
Acid startup
Chemistry balanced fairly easily without cya - I was going to add that after everything was completely done. Used tablets and liquid in the meantime
Sanding of bottom to remove visibly uneven plaster and pits
Very splotchy bottom where sanded
acid wash that wasn’t monitored - I called contractor when pool walls started turning dark green and I measured chlorine (0) an PH (magenta - definitely greater than 8.2)
contractor added baking soda and soda ash (used strips to measure)
Got TA to 50 and called it good.
I figured I could handle the rest. Had it test - ACH went from 220 preempt sanding to 480 post sanding (pool store measurement) and 850 - 1000 tfa test kit.
I added baking soda a couple of times, trying to raise TA slowly, then started noticing a lot of dust on bottom, and vacuum was picking it up. I thought plaster, then I thought baking soda (it fizzed with vinegar)
Came to this forum - saw filtration might be a problem, clean de filter completely.
saw expired baking soda could be a problem (mine was) and got new soda.
Problem continued, quit putting in baking soda.Of course I have to acid acid usually twice a day
the CH number going up Even after 5 inches of rain
how do I find out what is on the bottom of my pool?
Of course, now the pool is starting to look splotchy all over
Contractor is supposed to come out and drain some of the water in a couple days.

 

[hexabc]

Short story:
New tile, plaster and coping in February/March. Contractor was to turn over ready to swim
Acid startup
Chemistry balanced fairly easily without cya - I was going to add that after everything was completely done. Used tablets and liquid in the meantime
Sanding of bottom to remove visibly uneven plaster and pits
Very splotchy bottom where sanded
acid wash that wasn’t monitored - I called contractor when pool walls started turning dark green and I measured chlorine (0) an PH (magenta - definitely greater than 8.2)
contractor added baking soda and soda ash (used strips to measure)
Got TA to 50 and called it good.
I figured I could handle the rest. Had it test - ACH went from 220 preempt sanding to 480 post sanding (pool store measurement) and 850 - 1000 tfa test kit.
I added baking soda a couple of times, trying to raise TA slowly, then started noticing a lot of dust on bottom, and vacuum was picking it up. I thought plaster, then I thought baking soda (it fizzed with vinegar)
Came to this forum - saw filtration might be a problem, clean de filter completely.
saw expired baking soda could be a problem (mine was) and got new soda.
Problem continued, quit putting in baking soda.Of course I have to acid acid usually twice a day
the CH number going up Even after 5 inches of rain
how do I find out what is on the bottom of my pool?
Of course, now the pool is starting to look splotchy all over
Contractor is supposed to come out and drain some of the water in a couple days.View attachment 149846

You would need to reach extremely high levels of TA for baking soda to pecipitate to the pool bottom. Did you check if your filter is not ruptured and it doesn't leak the DE to the pool? Also, do you have a reliable test kit?

 

[gneissgirl]

I just took apart the filter, which was new last fall, and cleaned every fin. No holes. I don’t know how I could have put it together wrong, but I can’t rule that out. Here’s a couple of pictures.
My test kit was 2 years old so I ordered replacements that came in on Thursday. I got largely the same numbers. I am also confused on how the pool store numbers and mine could be so different. Of course, their acceptable range is different also. My TA right now is 36 by the pool store, 30 by my test.