refractometer calibration

ducati1212 · 02/20/2019, 08:08 PM

So I think my salt is off. I have a 3 month old red sea refractometer and 35 ppt calibration solution. I put the solution in tonight after not doing it in a month and my refractometer was reading high 40 ppt.

I adjusted it with the screw down to 35 and retested and it was fine.

I did the same thing 1/2 hour later and it was 40 ppt again. was just double checkig my work so I adjusted and got it to 35 ppt. waited 5 min tried again it was pretty close still.

now im curious so an hour later I get my solution and test again and its 40 ppt again. Now im not sure what my tank is

Can refractometers do this or am I just that rusty after an 8 year break. cant see what im doing wrong.

thoughts?

FishAndPhysics · 02/20/2019, 08:11 PM

Make sure the axles of the coverslip are moving freely, its important that the layer of saltwater is flat, not wedge shaped. This usually shows up in mine as a blurring of the line.

If I'm actually mixing saltwater right rather than just checking the salinity of my tank, I always calibrate first.

ryeguyy84 · 02/20/2019, 08:12 PM

Seems like somethings wrong with it. I stopped using my refractometer and bought one of these.

https://clearchoiceaquatics.com/coll...tester-hi98319

Love it so far, for the first week or 2 I checked it with my refractometer then stopped double checking.

Sent from my SM-G950U using Tapatalk

ducati1212 · 02/20/2019, 08:54 PM

Quote:

Originally Posted by ryeguyy84

Seems like somethings wrong with it. I stopped using my refractometer and bought one of these.

https://clearchoiceaquatics.com/coll...tester-hi98319

Love it so far, for the first week or 2 I checked it with my refractometer then stopped double checking.

Sent from my SM-G950U using Tapatalk

I just bought that an hour ago it comes in Tuesday. Until then I feel my salinity is at risk. I don’t get what I’m doing wrong I mean it’s a water drop

homer1475 · 02/21/2019, 06:07 AM

The Red Sea refractometer is known for not being able to hold it's calibration. Never read of it being this bad, but I have read about them drifting in a couple days of non use.

I have and use the milwaukee electric salinity tester. Just bought the hanna as it looks to be easier to use, and Hanna has a very good reputation in the hobby for reliable test kits.

ryeguyy84 · 02/21/2019, 06:16 AM

You're going to love it, dip, read, rinse. Calibration is just as easy and they recommend monthly

Sent from my SM-G950U using Tapatalk

02/20/2019, 08:08 PM	#1
ducati1212 Registered Member Join Date: Jul 2006 Location: Mass Posts: 604	refractometer calibration So I think my salt is off. I have a 3 month old red sea refractometer and 35 ppt calibration solution. I put the solution in tonight after not doing it in a month and my refractometer was reading high 40 ppt. I adjusted it with the screw down to 35 and retested and it was fine. I did the same thing 1/2 hour later and it was 40 ppt again. was just double checkig my work so I adjusted and got it to 35 ppt. waited 5 min tried again it was pretty close still. now im curious so an hour later I get my solution and test again and its 40 ppt again. Now im not sure what my tank is Can refractometers do this or am I just that rusty after an 8 year break. cant see what im doing wrong. thoughts?

02/20/2019, 08:11 PM	#2
FishAndPhysics Registered Member Join Date: Jan 2016 Location: NY Posts: 95	Make sure the axles of the coverslip are moving freely, its important that the layer of saltwater is flat, not wedge shaped. This usually shows up in mine as a blurring of the line. If I'm actually mixing saltwater right rather than just checking the salinity of my tank, I always calibrate first. __________________ 90 Gallon Mixed Reef with 20g sump Current Stock: 1 - Ocellaris Clownfish, 1 - Yellow Tang, 1 - Kole Yellow Eye Tang, 1 - unidentified hitchhiker goby, 1 - Coral Beauty, 3 - Lyretail Anthias.

02/20/2019, 08:12 PM	#3
ryeguyy84 Registered Member Join Date: Mar 2011 Location: New Jersey Posts: 2,753	Seems like somethings wrong with it. I stopped using my refractometer and bought one of these. https://clearchoiceaquatics.com/coll...tester-hi98319 Love it so far, for the first week or 2 I checked it with my refractometer then stopped double checking. Sent from my SM-G950U using Tapatalk __________________ Current tank: 90G mixed reef. Current Tank Info: 90 gallon

02/21/2019, 06:07 AM	#5
homer1475 Registered Member Join Date: Mar 2015 Location: Upstate NY Posts: 5,313	The Red Sea refractometer is known for not being able to hold it's calibration. Never read of it being this bad, but I have read about them drifting in a couple days of non use. I have and use the milwaukee electric salinity tester. Just bought the hanna as it looks to be easier to use, and Hanna has a very good reputation in the hobby for reliable test kits. __________________ 80G SCA Build: http://reefcentral.com/forums/showthread.php?t=2560256 Originally posted by der_wille_zur_macht: "He's just taking his lunch to work"

02/21/2019, 06:16 AM	#6
ryeguyy84 Registered Member Join Date: Mar 2011 Location: New Jersey Posts: 2,753	You're going to love it, dip, read, rinse. Calibration is just as easy and they recommend monthly Sent from my SM-G950U using Tapatalk __________________ Current tank: 90G mixed reef. Current Tank Info: 90 gallon