How much can source water affect alk/calc?

[AnomMatty]

Mixed new RODI water to 35ppm with Red Sea Coral Pro at 77F. Tested w/Salifert.
Alk: 14.7
Calc: 465
Mag: 1065

Salt is listed as mixing to:
Alk: 12.3-12.7
Calc: 455-475
Mag: 1360 - 1420 mg/l

Seems my Alk is exceptionally high, Calc dead on, and Mag is low (in before Randy says abandon Mag testing). Just curious if this could be from the source water, or something else. Don't have any other forms of tests, hoping to pick up Hanna Alk and Calc testers in the fairly near future.

 

[Randy Holmes-Farley Verified Community Expert]

If the water used is a few ppm or less of TDS, it is not impacting the parameters. Either the salt does not match the specs, the kits are off, or the salinity is off off the value used to set the specs.

I have low confidence in magnesium testing.

 

[AnomMatty]

If the water used is a few ppm or less of TDS, it is not impacting the parameters. Either the salt does not match the specs, the kits are off, or the salinity is off off the value used to set the specs.

I have low confidence in magnesium testing.

Thank you sir. I plan to retest today or tomorrow to confirm, but knowing the source water isn't a factor is one less thing to worry about. Are there any methods of Alk/Calc testing you've found more reliable than others?

Also want to say appreciate all the time and info you dedicate here. Helps to have reliable and trusted sources for us newer folks.

 

[javajaws]

Doesn't coral pro salt have an advertised alk of 12 dkh? This doesn't seem so out of line for that salt. I'd recommend a different salt it that's not near the target dkh you want.

 

[AnomMatty]

Doesn't coral pro salt have an advertised alk of 12 dkh? This doesn't seem so out of line for that salt. I'd recommend a different salt it that's not near the target dkh you want.

12.3-12.7 -- I just felt like 14.7 was abnormally high vs what it is advertised as.