Hach 44600 conductivity meter

[Cory]

Wow it came out the nearly same as my sybon refractometer and tropic marin floating hydromter!

The reading was 18.6 mS/c and which is 11.7 ppt and coverted my tanks salinity is 35.1 according to a 30 year old hach! I even verified the digital thermometer is good and is the same as my glass thermometer. Heres some pics:

 

[Cory]

The result

 

[Randy Holmes-Farley Verified Community Expert]

Good to hear!

 

[Cory]

So is there a way to use this to mix salt into water? Or i gotta buy another meter lol? And its actually more than 40 years old wow.

 

[Randy Holmes-Farley Verified Community Expert]

So is there a way to use this to mix salt into water? Or i gotta buy another meter lol? And its actually more than 40 years old wow.

Only by dilution, I'm afraid.

 

[Cory]

This will read limewater potency right?

 

[Randy Holmes-Farley Verified Community Expert]

Yes. 10.3 mS/cm is about saturation.

 

[Cory]

If 35 ppt seawater is 53 mS/cm, and you can only read 20 mS/cm, I'd mix 2 parts RO/DI fresh water and 1 part seawater, to get about 17.6 mS/cm. Mix them by weight or volume. Weight is ideal.

use the calculator to get the PPT (=PSU), and multiply by 3.

I know this was an old post but when you say mix by weight to do this, would you mix 100g of saltwater and 200g of ro water? Because 100 g of saltwater is like 120ml.

 

[Randy Holmes-Farley Verified Community Expert]

I know this was an old post but when you say mix by weight to do this, would you mix 100g of saltwater and 200g of ro water? Because 100 g of saltwater is like 120ml.

100 g of saltwater should be about 97.7 mL at room temp. It’s density is about 1.0236 g/mL.

 

[Cory]

100 g of saltwater should be about 97.7 mL at room temp. It’s density is about 1.0236 g/mL.

I must be missing something. If 100ml of ro water weighs 100 grams then why does 97.7 ml of saltwater which has salt in it take up less volume? Salts are more dense than water? Thats interesting. So if we took all the salt from the sea it would raise the sea level?

 

[Randy Holmes-Farley Verified Community Expert]

I must be missing something. If 100ml of ro water weighs 100 grams

It does not. That's a simplification for noncritical measurements.

The density of totally pure fresh water at 25 deg C is 0.997 g/mL, so 100 ml weighs 99.7 g.

The density of seawater at 25 deg C is 1.0236 g/mL, so 100 mL weighs 102.36 grams, and 100 grams takes up 97.7 mL.

 

[Randy Holmes-Farley Verified Community Expert]

If you removed all the salts from 100 mL of seawater (= 102.36 g; it contains 3.5 g of salts), you would have 102.36 g - 3.5 g = 98.86 grams of pure fresh water, and (with a density of 0.997 g/mL) it would occupy 0.992 mL, so the volume declines.