I run my system at 1.029 [ ! ]

Jlobes · Jan 19, 2016

so youre taking the claims/words of one person and their opinion about a piece of equipment(refractometer) and implying that its true? what "research" was done by nantopia? with what evidence to support that refractometers are inaccurate and read high?
its a tool, that does a specific job and can be calibrated for accuracy. Im not sure why the sentiment of anti/against or refusing to accept the reading of refractometers.
Many hobbyists, scientists and researchers use this tool daily for all sorts of purposes, but specifically to test/read SG... thats what it does.
no reason to throw it in the trash or dismiss it, if you think yours are incorrect, calibrate and try again. perhaps, get another.

i use a refract. daily for my tank and calibrate daily with solution. I suppose the solution could be improperly made, but cant think of any reason why it would read higher than actual.

Berlibee · Jan 19, 2016

Please read again more carefully @Jlobes

I'm not saying it's TRUE, I'm not asking how to calibrate my refractometers, I'm saying that this person got nice results by trusting the probe. I've tested her way and I've nice results as well after 5 weeks.
I'm not saying it's the way to go, I'm asking "Is it possible that it's true?" and I've ordered a lab test to verify this information I'm not on one side or another.

You're not reading all the posts, you're talking again and again about calibration. If you want make an input to the topic please read before it's will help
to stay on the track and avoid misunderstanding.

I'm not here to promote this method, I think it's an interesting opinion and I want to understand if it's true.

If it's not interesting for you and you trust your refractometers all good.

Cheers !

Berlibee · Jan 19, 2016

Randy Holmes-Farley said:
I agree that conductivity is a great method, and is my method of choice, using an Orion Model 128 (expensive) and a Pinpoint. My article on how it works at Reef Edition should come out any day now.

My concern with salinity by conductivity using hobby controllers is the complexity of such issues as calibration and possibly having independent temperature and conductivity sensors (in my meters they are in one unit). For whatever reasons these devices seem to give people problems that more simple devices do not.

FWIW, simple does not mean less capable. My Orion is a very expensive device with a much better probe (4 electrodes) than moss hobby units would use (often only 2 electrodes), but it cannot even have its calibration adjusted (at least not without opening the case and messing with the internals, which I have never tried). That way, it can never be miscalibrated, and if it is off (mine has always read high by about 2.7%) you make the corrections manually (assuming you care at that level of accuracy).

As to the comments about refractometers above, some of it is true, but using a good 35 ppt standard eliminates nearly all of the concerns (except temperature, which an ATC probe should automatically correct for a range of temperatures, but having everything at the same temp eliminates that concern too).

The Milwaukee is also one of the true seawater refractometers mentioned. When folks have calibrated them in RO/DI and then tested them in 35 ppt standards, they get good agreement as best I've seen. It is not the case that they generally "read high".

Nice, yes I've read a lot of opinions that Apex probe is not very accurate as well. But also many of these opinions were based on a wrong calibration process.

wpeterson · Jan 19, 2016

Randy Holmes-Farley said:
My concern with salinity by conductivity using hobby controllers is the complexity of such issues as calibration and possibly having independent temperature and conductivity sensors (in my meters they are in one unit). For whatever reasons these devices seem to give people problems that more simple devices do not.

I agree with what Randy has said here, I'm sure the Orion unit used by Randy is much more accurate than a cheap refractometer.

However, when it comes to the hobby the question is how accurate the readings are for most people over time. Here, I would argue a simpler device, calibration, or testing methodology will produce better results over time for most hobbyists. This is why an inexpensive refractometer calibrated to 35ppt fluid will probably produce better results for most hobbyists over time than the Apex salinity probes. The apex probes seem difficult to calibrate properly and keep calibrated and free of skewing circumstances (air bubbles, etc).

Berlibee · Jan 19, 2016

I agree @wpeterson it's much more easy to use a refractometer and you can't go wrong with it. Even if it's not that accurate ( I'm not saying it is ) you will hit the "acceptable" levels and the system will be fine.

wpeterson · Jan 19, 2016

The question of what salinity you should run your reef at is a different matter. Randy provided great evidence of natural reefs with salinity varying from 1.025 to 1.029 in the Red Sea. It sounds like @Berlibee has raised his salinity to 1.029 without negative impact on his tank.

For the hobby, I would think that stability of salinity is more important than what salinity level you target as long as you're within healthy ranges (1.024-1.029?). Most of the creatures can comfortably come to an equilibrium with the environment, but the drop/rise in salinity are what induce the most stress - especially for sensitive invertebrates.

I choose to run my reef at 1.025 because it's close to the salinity of most natural reefs, most hobbyists, and LFS. This makes acclimating newcomers to my tank easier when there's less of a differential. If you choose to run your tank at 1.029 and add critters from a 1.025 system, you're probably looking at drip acclimating for many hours to prevent a salinity shock. You're also spending more money on salt to maintain a higher salinity level. I don't think there's any harm in running higher salinity, but there doesn't seem to be compelling evidence of a benefit.

Berlibee · Jan 19, 2016

Stability is the key ...

Berlibee · Jan 25, 2016

Triton Test Kit is here. Will ship it tomorrow.

Berlibee · Jan 27, 2016

Alkalinity: 8.0 (Salifert)
Po4: 0.02 (Hanna ULR)
Ca: 420 (Red Sea)
No3: 2 - 4 (Salifert)
Salinity: 1.029 (Digital Refractometer) / 1.026 (Apex Probe)

Triton Test Sent.
These are the parameters tested at home.

Berlibee · Feb 4, 2016

Water samples received by the lab 2 days ago. Do you know guys when results are posted in average?

jason2459 · Feb 4, 2016

I've been getting results back in about 7 business days from the time I sent in the samples. Fastest was 5 business days.

Berlibee · Feb 4, 2016

Thank you, I've sent it 01/27/2016, on the package it was saying 7 - 10 days transport and testing. So it's very close, maybe even tomorrow.

JimWelsh · Feb 4, 2016

Berlibee said:
Awesome, I hope Triton will clarify this situation.
But if Triton will say that I really have 1.029 I will be in a very difficult situation.

Last time I looked, Triton doesn't give a result for salinity, unless that is something they have recently added. I have put together a spreadsheet that estimates salinity based on Triton results, though.