Salt Mixing Problems

[Rog]

Hi,

Thanks for your reply. Sorry yes, it is 3.34 meq/L. 9.35 dKH.

I'm setting up an experiment with tapwater and RO from the grocery store.

Rog

[SoloSK71]

Leave the water to sit for at least 24 hours with a water pump that causes surface agitation. Add a heater to bring it up to tank temperature. This can be turned off after if you are not going to use the water right away. Then when you are mixing your salt, leave the water pump and heater running for another 12 to 24 hours afterwards.

I have seen low pH water from CO2 cause problems with Calcium and Magnesium when mixing salt before. Low temperature and lack of mixing have caused issues with cloudiness/precipitation.

Charles

[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...