Calibration fluid?

[Notsolostfish]

What calibration fluid i should be using for my ma877 milwaukee? I ran out. And people said using rodi wont give accurate results is that true?

 

[caddnima_reef]

Get the 35ppt one....

 

[Notsolostfish]

Get the 35ppt one....

Iv been calibrating with rodi is that bad?

 

[caddnima_reef]

I am not sure. Since you are running and testing at 35ppt, my question to you is how do you know if your refractometer is correct at 35ppt? So I always test at 35ppt since that is the most important number for me. I don't care if 30 is wrong, or 40 is wrong.... What I care about is 35ppt.... Hope this make sense.

 

[homer1475]

With the milwaukee you don't actually "calibrate" the machine, but rather "zero" it out. Then use a a known solution to see of the "zeroing" took correctly.

You need to use distilled or deionized water to zero out the machine.

 

[Notsolostfish]

With the milwaukee you don't actually "calibrate" the machine, but rather "zero" it out. Then use a a known solution to see of the "zeroing" took correctly.

You need to use distilled or deionized water to zero out the machine.

Not rodi?

 

[KStatefan]

Not rodi?

RODI stands for Reverse Osmosis De-ionized

 

[Notsolostfish]

RODI stands for Reverse Osmosis De-ionized

So i can use it. Right? Im confused

 

[Randy Holmes-Farley Verified Community Expert]

So i can use it. Right? Im confused

yes.

you can also check the device with a 35 ppt seawater refractometer standard.

 

[Notsolostfish]

yes.

you can also check the device with a 35 ppt seawater refractometer standard.

I tried both rodi and destilled yesrerday and their solution showing 1.026 instead of 1.025 this is frustrating

 

[Randy Holmes-Farley Verified Community Expert]

I tried both rodi and destilled yesrerday and their solution showing 1.026 instead of 1.025 this is frustrating

All within the manufacturer specifications for your device.

if you want to distinguish 1.025 from 1.026 you may need a different device.

 

[Notsolostfish]

All within the manufacturer specifications for your device.

if you want to distinguish 1.025 from 1.026 you may need a different device.

So like if its showing the solution at 1.026 and its 1.025. And my tank showing at 1.026 is that means my tank is 1.025 or 1.026 or 1.027 lol how would i know.

 

[Randy Holmes-Farley Verified Community Expert]

So like if its showing the solution at 1.026 and its 1.025. And my tank showing at 1.026 is that means my tank is 1.025 or 1.026 or 1.027 lol how would i know.

With the device you are using, a true 1.026 shows as anywhere from 1.024 to 1.028, even when perfectly calibrated.

 

[Notsolostfish]

With the device you are using, a true 1.026 shows as anywhere from 1.024 to 1.028, even when perfectly calibrated.

So basically if my tank is 1.027 theres no way to tell. What should i do? I dont want 1.027 salinity was aiming at 1.026

 

[EricR]

With the device you are using, a true 1.026 shows as anywhere from 1.024 to 1.028, even when perfectly calibrated.

This is probably a silly question but...

If device accuracy is +/- 2 ppt, would you expect it to be consistently low/high by the same amount (with same calibration) or would you expect each test on same sample to vary by that amount from test to test?

 

[Notsolostfish]

With the device you are using, a true 1.026 shows as anywhere from 1.024 to 1.028, even when perfectly calibrated.

So how do i get exact number

 

[LeftyReefer]

So how do i get exact number

Floating Hydrometer.

but they are a pain to use and extremely easy to break, so not something you want to have to rely on for day to day salinity testing.

Salinity of ocean water varies a bit depending on many conditions, so a little variation won't hurt anything as long as it's close. Most common methods will get you close enough.

 

[Notsolostfish]

Floating Hydrometer.

but they are a pain to use and extremely easy to break, so not something you want to have to rely on for day to day salinity testing.

Salinity of ocean water varies a bit depending on many conditions, so a little variation won't hurt anything as long as it's close. Most common methods will get you close enough.

I have one sitting in the box how do i use it they told me i nwed 500ml or something for it i forgot

 

[Derrick0580]

Floating Hydrometer.

but they are a pain to use and extremely easy to break, so not something you want to have to rely on for day to day salinity testing.

Salinity of ocean water varies a bit depending on many conditions, so a little variation won't hurt anything as long as it's close. Most common methods will get you close enough.

Exactly! I bought 35ppt calibration fluid and calibrated my refractometer with it then checked against a tropic marin pro floating hydrometer and the calibration fluid was way off so I calibrated with 0 tds rodi and then the refractometer matched the floating hydrometer perfectly!

 

[LeftyReefer]

I have one sitting in the box how do i use it they told me i nwed 500ml or something for it i forgot

You float in in your water. but in order to get an accurate reading and to keep it from bobbing all around and breaking on your tank or rocks, you'll probably need to turn off all your pumps/wave makers to get an accurate reading on it. Plus the temperature of the water matters with them.

or you can get a different container, fill it with your water and then float the hydrometer in that.... so it will need to be a taller vessel. Keep in mind water temp matters, so that will have to be considered too.

All of which is a PITA, so that is why they are not super popular for daily testing.

But the good ones are very accurate when used correctly.