Salt Mixing Problems

[Rog]

Using 145g of Salinity Salt mixed with 4L of RO (no DI) batch bought from the store:

Temp 22.4C
SG: 1.026 (Selbon refractometer - checked calibration today)
Salinity: 35ppt
pH: 8.77 (pinpoint pH monitor)
Alk: 3.17meq/L 8.9dKH (Hanna colorimeter)
Ca: 330 ppm (Red Sea Reef Foundation Pro)
M: 960 ppm (Red Sea Reef Foundation Pro)

(I validated the test kits with other test kits last night and a reference sample).

Okay, so it's not just my water that is causing this problem. This constant testing is getting time-consuming and expensive... however, I won't subject my animals to this mess and will need to keep trying and testing til I get more appropriate results.

Rog

[SoloSK71]

Just to confirm, did you test the pH before adding salt?

Charles

[Rog]

Hi SoloSK71,

Thanks for the advice on letting the water sit for 24 hours prior to adding salt.

Yes I measured the pH before adding salt, it was was 7.8.

Rog

[Rog]

I learned something very interesting in this process. my Selbon refractometer I've been using for years, although calibrates perfectly with the solution isn't quite right.

Apparently the Selbon refractometer sold in pretty much all marine aquarium stores is meant for brine solutions, and although close, isn't quite as accurate for seawater specifically. I was at J&L yesterday and tried a new bottle of 35 ppt Selbon calibration fluid on a few other refractometers. Very interesting. The sample that read 1.026 on my freshly calibrated Selbon showed 1.024 on two other refractometers...