Well, I got the results, let's say it's interesting...

I planned to send in the water sample last monday but I couldn't make it, so I've send it in last tuesday.
I also tested te very same samplewater with my iDip, latest app version, THU and CAH.
Rinsed and cleaned the cell very carefully every time and tried to keep a constant pace swiping the strip and meanwhile looking at the seconds counting down on the iDip.
Now and then touching the bottom of the cell with the strip, while swiping, to be sure it was dipped in correctly.
I tested the sample water twice, here are the results.
First iDip test cycle:
KH: 8,85 dKH
PH: 8,0 PH
Hardness: 6537 ppm
CA: 444,80 ppm (as CA)
MG: 1317,19 ppm (as Mg+2)
PO4: LO ppm
NO3: LO (as NO3)
Second iDip test cycle:
KH: 8,29 dKH
PH: 8,0 PH
Hardness: 6783 ppm
CA: 445,60 ppm (as CA)
MG: 1376,43 ppm (as Mg+2)
PO4: LO ppm
NO3: LO (as NO3)
I did the more simple lab test this time, here are the results:
https://www.reef2reef.com/attachmen...5/?temp_hash=c1a5940ea9e7707662b8d374377c9222
I was a bit surprised when I looked at the lab results concerning KH and PH...
A PH of 7,14 PH is way (!) too low...

And, the ALK is too high, just above 10 dKH.
I did a quick check with a JBL test strip and I must say, eventhough it's not always easy to read, the PH looks a bit on the low side.
I mean more in the direction of 7 than it is to 8.
I also checked with Salifert, again I think the PH might be off.
Also tested the ALK with a Salifert test: 9,9 dKH.
It's in the evening overhere and I stopped dosing my natriumbicarbonate/natriumcarbonate mix and also stopped dosing my carbon source (vinegar) for now.
I will take a water sample to the European distributor (Veldhuis Aquaria) tomorrow and see what they think about the PH and ALK.
What do you think about CA and MG?
I think it's not bad at all !
I'll keep you posted...