Which salinity device to trust?

serwobow

Well-Known Member
BRS Member
#1
So, I have had my mixed reef tank for about 10 years now, keeping a wide variety of SPS and LPS. Tank seems pretty good, but not great to me. My acroporas (about 15 different ones) are doing ok, but don't have the extension or color that I'd like. Been measuring salinity with a cheap $10 hydrometer for the whole time, keeping the salinity at 1.026 (or so I thought...you know where I am going with this). The other day on Boston Reefers I saw an inexpensive refractometer for sale, so I bought it. I bought some fresh BRS salinity standard to calibrate it. This device told me my salinity was 1.030, which is the upper limit of what's supposed to be ok. So, what to do? Will I see improvements by dropping my salinity to a more normal range? Does anyone know? Looking for opinions on the importance of keeping salinity at 1.025-1.026 versus 1.030.
 

Chris A.

Formally toomanyfish
BRS Member
Officer
#2
It’s on the high side and that means all your other readings will drop once you start correcting your salinity.
I’d just do your normal water changes with the correct salinity until you reach your desired level. This way you won’t sway your other levels as much and cause more issues
 

Rambler67

Well-Known Member
BRS Member
#3
Yea I trust the refractometer better than the hydrometer. Just get some calibration fluid to check its acuret. Yea that's on the higher end the lower the salinity the better the o2 saturation would be so I think it would help. As chris said i would just lower the salinity in the water changes to bring it down slowly.
 

aresangel

Tim- 2019 BRS President
BRS Member
Officer
#4
Agree with above. Find your constant and you can use the hydrometer much quicker. Consistency as just as important as level in some cases. As you mentioned above it has worked so far! Plus some oceans run higher than others and we make up this preferred number for us to conform to. So I would slowly turn it down to a compromise level between the two and maintain stability.
 

dz6t

Acro Garden, BRS Sponsor
BRS Member
#5
1.030 is not bad, some coral reef are at that level. Salinity lower than 1.023 actually can affect coral.
Refractometer is a hit or miss, it can be worst than a swing arm hydrometer if calibrated wrong, such as using RO water instead of standard solution.



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serwobow

Well-Known Member
BRS Member
#6
1.030 is not bad, some coral reef are at that level. Salinity lower than 1.023 actually can affect coral.
Refractometer is a hit or miss, it can be worst than a swing arm hydrometer if calibrated wrong, such as using RO water instead of standard solution.

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That is what I am worried about - going lower and really causing a problem. But, I think the refractometer is probably right, because my Mg levels have always been higher than expected, like above 1500, and I never knew why. The difference between 1.025 and 1.030 salinity equates to Mg levels increasing from 1350 to about 1600, so I think the increased salinity explains my high Mg levels. Anyways, I think I will begin to slowly drop it down as recommended above. I'm gonna buy one additional salinity calibration fluid just to make sure though. Have read a few online comments where people claim their calibration fluid was off.
 

dz6t

Acro Garden, BRS Sponsor
BRS Member
#7
Agree with the calibration fluid. Some are off, I tried several brands and they are not consistent within the same brand, lol.
I have to get a standard seawater sample from a lab, lol.
But to be safe, keep salinity around 1.026 to 1.028.




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serwobow

Well-Known Member
BRS Member
#8
Agree with the calibration fluid. Some are off, I tried several brands and they are not consistent within the same brand, lol.
I have to get a standard seawater sample from a lab, lol.
But to be safe, keep salinity around 1.026 to 1.028.


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That is funny. I should be using water from one of your tanks to calibrate. At least then I know it is at a salinity that works well.
 

Cpage101

Corey- 2019 BRS BOD
BRS Member
Officer
#10
Just picked up the Hanna salinity tester the thing is spot on and super easy!


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Aquatic Nerd

(Formerly SeventyTimes7) Yung Jacques Cousteu
BRS Member
Officer
#13
I used the Scionix Pen from Logan at Reef Breeders. It works great, comes with a little bottle of calibration fluid.
 

dz6t

Acro Garden, BRS Sponsor
BRS Member
#15
I use Hanna digital meter for casual checking, a calibrated refractometer as standard method. Digital meter requires more calibration than refractometer.


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Cpage101

Corey- 2019 BRS BOD
BRS Member
Officer
#16
I use Hanna digital meter for casual checking, a calibrated refractometer as standard method. Digital meter requires more calibration than refractometer.


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I agree with Dong I have both Digital meter is recommended to calibrate monthly. This being said you still need to check calabration on your refractometer from time to time with 35PPM calabration fluid also.


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serwobow

Well-Known Member
BRS Member
#17
If there is inconsistent calibration fluid this would be nightmare. Dong what do you use? Anything anyone else trust?
I agree - a bad calibration standard is just as bad as a bad hydrometer.
I bought my standard from BRS, but I really just had to trust it. Using that standard, I now think that my current salinity is 1.027, but I don't actually know.

Next time, I am going to get big bottle of tank water directly out of a friends thriving reef tank, and then calibrate using that. The advantage is that you know that the tank water works well, so it must be close to optimal. Another advantage is that you can get a little larger volume than the 250ml from BRS.
 

Sparky88

Well-Known Member
BRS Member
#18
So basicaly go to the best reefer you no and grab his water an match it. The anal retentive side of me hates that idea. Dz6t how much for your salt water standard. Lol does using this get me a torch garden like yours
 

FREAKINRICAN69

Well-Known Member
BRS Member
#19
I found the Hanna digital salinity/temperature meter is the most accurate and consistent digital meter.


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I agree with Acro. Ever since i invested in the Hanna Salinity & temp checker i have better control of the tanks i'm running. Now i'm slowly adjusting salinity due to the differences in the prior refractometers i was using before.
 

dz6t

Acro Garden, BRS Sponsor
BRS Member
#20
My water is 1 million $ per gallon...
Just kidding.
I give away my saltwater all the time.


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