Refractometer

[Pszemol]

What refractometer do you use for your tanks?

How precise measurement does it allow you to do?

I have RHS-10ATC and it has 1 division per 1 ppt,
total 100 divisions in the range from 0 to 100ppt.

If yours is more acurate than 1ppt/0.001 SG
or has scale for smaller range than 0-100ppt
please list the manufacturer/model# - thanks!

[Boomer]

Pszemol

About 95 % of the expensive refracts, $200-$300, only go to 1 ppt

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If You See Me Running You Better Catch-Up
"Pszemol" > wrote in message ...
: What refractometer do you use for your tanks?
:
: How precise measurement does it allow you to do?
:
: I have RHS-10ATC and it has 1 division per 1 ppt,
: total 100 divisions in the range from 0 to 100ppt.
:
: If yours is more acurate than 1ppt/0.001 SG
: or has scale for smaller range than 0-100ppt
: please list the manufacturer/model# - thanks!

[Pszemol]

"Boomer" > wrote in message ...
> About 95 % of the expensive refracts, $200-$300, only go to 1 ppt

Thanks, so why people say refracts are so acurate and reliabe?
People can get acuracy 0.001 sg with cheap Deep Six swing arm.

Are we paying more just to have a convenience of refractometer?

[Boomer]

There is less error involved with a refract. I have yet seen a Deep-Six that is even close
to what it should read. Swing arms units also have a habit of collecting salt deposits on
the swing arms and pin, which can cause very low readings. Thus, they need to be soaked in
vinegar every month to remove such deposits. Floating hydrometers have the issue of temp
compensation, where most in this hobby seem to get lost. Refracts are much more accurate
out of the box. However, they are also in error but we can compensate for that. For the
last couple of months Randy and I have been colleting data so he could redo the old DIY
calibration solutions from months ago. We knew something was wrong with them and we wanted
something reefers could make easily for a DIY calibration solution. The first ones we had
were to low. In short your refract reads 1.5 ppt to low. So if you want a salinity of 35
ppt (3..5 %), on your refract, it needs to read 36.5, which equals 35 ppt NSW. Refracts
from the factory are not calibrated to seawater but NaCl, which does not have the same RI
( Refractive Index) as NSW. You can read all about it here. It just came out the other day
:-)

http://reefkeeping.com/issues/2004-06/rhf/index.htm

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If You See Me Running You Better Catch-Up
"Pszemol" > wrote in message ...
: "Boomer" > wrote in message
...
: > About 95 % of the expensive refracts, $200-$300, only go to 1 ppt
:
: Thanks, so why people say refracts are so acurate and reliabe?
: People can get acuracy 0.001 sg with cheap Deep Six swing arm.
:
: Are we paying more just to have a convenience of refractometer?

[Pszemol]

"Boomer" > wrote in message ...
> There is less error involved with a refract. I have yet seen a Deep-Six that is even close
> to what it should read. Swing arms units also have a habit of collecting salt deposits on
> the swing arms and pin, which can cause very low readings. Thus, they need to be soaked in
> vinegar every month to remove such deposits. Floating hydrometers have the issue of temp
> compensation, where most in this hobby seem to get lost. Refracts are much more accurate
> out of the box. However, they are also in error but we can compensate for that.

Looking at the scale of mine refractometer with divisions for 34 and 35 ppt so close
to each other and comparing wide scale of swing arm with a centimeter between 34 and 36
is it hard to believe refractometers are "much more accurate"... But I will take your word.

Also, would you agree that Coralife statement of +/-0.001 SG accuracy of their
DEEP SIX is not true if you say +/- 1ppt refractometer is "much more accurate"?

> For the
> last couple of months Randy and I have been colleting data so he could redo the old DIY
> calibration solutions from months ago. We knew something was wrong with them and we wanted
> something reefers could make easily for a DIY calibration solution. The first ones we had
> were to low.

I will wait then... thanks. But now I remember I have a postal scale with 1g acuracy...
It should give me acurate enough result for the calibration.

> In short your refract reads 1.5 ppt to low. So if you want a salinity of 35
> ppt (3..5 %), on your refract, it needs to read 36.5, which equals 35 ppt NSW. Refracts
> from the factory are not calibrated to seawater but NaCl, which does not have the same RI
> ( Refractive Index) as NSW. You can read all about it here. It just came out the other day
> :-)

Thank you.
So it looks like people adjusting their tanks to a refractometer reading 35 ppt
are really using sea water with less than 34 ppt of salt in it... Adding on top
of it +/- 1ppt manufacturer stated measurement error margin we could be off by
more than 2.5 ppt if we do not correct NaCl offset... Sounds very pessimistic :-)

[Boomer]

"Also, would you agree that Coralife statement of +/-0.001 SG accuracy of their
DEEP SIX is not true if you say +/- 1ppt refractometer is "much more accurate"?"

If you went out and bought 10 of each the refracts would be 9 out of 10, right on for a 35
ppt NaCl solution. The Deep-Six, 9 out of 10 would be all over the place.

" We knew something was wrong with them and we wanted
something reefers could make easily for a DIY calibration solution. The first ones we had
were to low."

AND

"I will wait then... thanks. But now I remember I have a postal scale with 1g accuracy...
It should give me accurate enough result for the calibration.""

You don't have to wait it has already been done go back and re-read the other post, that
is the new one. I gave a link to it.

" Adding on top
of it +/- 1ppt manufacturer stated measurement error margin we could be off by
more than 2.5 ppt if we do not correct NaCl offset..."


They are rarely off that much. What that means is that they guaranteed no more than that.
Even a $250 NIST certified hydrometer is + / - .001. Even the $ 600 fiberoptic
refract , for SEAWATER is only +/- 1 ppt. If you want to get accurate you need a
conductivity meter starting a + $400 to get it to 0.1 ppt.

If you use our stds. you will know exactly where you are at, with the refract and
Deep-Six


Boomer

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If You See Me Running You Better Catch-Up
"Pszemol" > wrote in message ...
: "Boomer" > wrote in message
...
: > There is less error involved with a refract. I have yet seen a Deep-Six that is even
close
: > to what it should read. Swing arms units also have a habit of collecting salt deposits
on
: > the swing arms and pin, which can cause very low readings. Thus, they need to be
soaked in
: > vinegar every month to remove such deposits. Floating hydrometers have the issue of
temp
: > compensation, where most in this hobby seem to get lost. Refracts are much more
accurate
: > out of the box. However, they are also in error but we can compensate for that.
:
: Looking at the scale of mine refractometer with divisions for 34 and 35 ppt so close
: to each other and comparing wide scale of swing arm with a centimeter between 34 and 36
: is it hard to believe refractometers are "much more accurate"... But I will take your
word.
:
: Also, would you agree that Coralife statement of +/-0.001 SG accuracy of their
: DEEP SIX is not true if you say +/- 1ppt refractometer is "much more accurate"?
:
: > For the
: > last couple of months Randy and I have been colleting data so he could redo the old
DIY
: > calibration solutions from months ago. We knew something was wrong with them and we
wanted
: > something reefers could make easily for a DIY calibration solution. The first ones we
had
: > were to low.
:
: I will wait then... thanks. But now I remember I have a postal scale with 1g acuracy...
: It should give me acurate enough result for the calibration.
:
: > In short your refract reads 1.5 ppt to low. So if you want a salinity of 35
: > ppt (3..5 %), on your refract, it needs to read 36.5, which equals 35 ppt NSW.
Refracts
: > from the factory are not calibrated to seawater but NaCl, which does not have the same
RI
: > ( Refractive Index) as NSW. You can read all about it here. It just came out the other
day
: > :-)
:
: Thank you.
: So it looks like people adjusting their tanks to a refractometer reading 35 ppt
: are really using sea water with less than 34 ppt of salt in it... Adding on top
: of it +/- 1ppt manufacturer stated measurement error margin we could be off by
: more than 2.5 ppt if we do not correct NaCl offset... Sounds very pessimistic :-)

[Pszemol]

"Boomer" > wrote in message ...
> They are rarely off that much. What that means is that they guaranteed no more than that.
> Even a $250 NIST certified hydrometer is + / - .001. Even the $ 600 fiberoptic
> refract , for SEAWATER is only +/- 1 ppt. If you want to get accurate you need a
> conductivity meter starting a + $400 to get it to 0.1 ppt.

I am surprised with the amount of money this kind of ohm-meter costs...
Is the electrode so expensive? The meter itself should be dirt cheap.

> If you use our stds. you will know exactly where you are at, with the refract and
> Deep-Six

Good idea.

[Boomer]

The probes are cheap, it is the meter that is expensive. Go here for a look :-)

www.coleparmer.com

Type in Conductivity in the search window. The click on Conductivity , then Portable
Meters

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If You See Me Running You Better Catch-Up
"Pszemol" > wrote in message ...
: "Boomer" > wrote in message
...
: > They are rarely off that much. What that means is that they guaranteed no more than
that.
: > Even a $250 NIST certified hydrometer is + / - .001. Even the $ 600 fiberoptic
: > refract , for SEAWATER is only +/- 1 ppt. If you want to get accurate you need a
: > conductivity meter starting a + $400 to get it to 0.1 ppt.
:
: I am surprised with the amount of money this kind of ohm-meter costs...
: Is the electrode so expensive? The meter itself should be dirt cheap.
:
: > If you use our stds. you will know exactly where you are at, with the refract and
: > Deep-Six
:
: Good idea.

[Pszemol]

"Boomer" > wrote in message ...
> The probes are cheap, it is the meter that is expensive. Go here for a look :-)
>
> www.coleparmer.com
>
> Type in Conductivity in the search window. The click on Conductivity ,
> then Portable Meters

Do not understand these prices... Why is it so expensive? :))
The only reason which I could guess is "not mass produced".
There is less electronics in this kind of meter than in
a $20 multimeter from Walmart... What a strange world :))
I need to make this kind of meter myself :-))

[Eric]

Pszemol wrote:
> Looking at the scale of mine refractometer with divisions for 34 and 35 ppt so close
> to each other and comparing wide scale of swing arm with a centimeter between 34 and 36
> is it hard to believe refractometers are "much more accurate"... But I will take your word.
>
> Also, would you agree that Coralife statement of +/-0.001 SG accuracy of their
> DEEP SIX is not true if you say +/- 1ppt refractometer is "much more accurate"?

A measurement tool is more PRECISE if it can measure to a greater number
of significant digits. The Deep Six is a more precise measuring device.

A measurement tool is more ACCURATE if it can come closer to the true
value of whatever it is you're measuring. The refractometer is more
accurate.

From this, hopefully it's clear that it does no good to be more precise
if the instrument is not accurate. We use refractometers because they
are fairly accurate. Unfortunately, they are not very precise.

Eric

[Mike Imbler]

Good posting Eric,
In my work we've used the terms resolution capability versus accuracy,
but they mean exactly what you have defined as precise versus accuracy,
Mike
"Eric" > wrote in message
...
> Pszemol wrote:
> > Looking at the scale of mine refractometer with divisions for 34 and 35
ppt so close
> > to each other and comparing wide scale of swing arm with a centimeter
between 34 and 36
> > is it hard to believe refractometers are "much more accurate"... But I
will take your word.
> >
> > Also, would you agree that Coralife statement of +/-0.001 SG accuracy of
their
> > DEEP SIX is not true if you say +/- 1ppt refractometer is "much more
accurate"?
>
> A measurement tool is more PRECISE if it can measure to a greater number
> of significant digits. The Deep Six is a more precise measuring device.
>
> A measurement tool is more ACCURATE if it can come closer to the true
> value of whatever it is you're measuring. The refractometer is more
> accurate.
>
> From this, hopefully it's clear that it does no good to be more precise
> if the instrument is not accurate. We use refractometers because they
> are fairly accurate. Unfortunately, they are not very precise.
>
> Eric

[Pszemol]

"Eric" > wrote in message ...
> A measurement tool is more PRECISE if it can measure to a greater number
> of significant digits. The Deep Six is a more precise measuring device.
>
> A measurement tool is more ACCURATE if it can come closer to the true
> value of whatever it is you're measuring. The refractometer is more
> accurate.
>
> From this, hopefully it's clear that it does no good to be more precise
> if the instrument is not accurate. We use refractometers because they
> are fairly accurate. Unfortunately, they are not very precise.

:-)
I guess I understand the difference between precision and accuracy, and it
looks to me, a good accuracy is not worth anything without a good precision...

A meter cannot be more accurate than 1ppt if it is not precise to a single ppt.
Highly compressed scale on the refractometer hardly guarantee 1 ppt
precission, which means the accuracy is not better than 1ppt as well...

What refractometer gains on accuracy it looses on precission to swing arm.
I would risk the statement a nicely calibrated (checked with the standard)
swing arm could be more accurate than refractometer because of
its greater precision :-)

[Eric]

Terminology quibles aside, you're quite right. Unfortunately most swing
arm devices don't seem to be well calibrated, and are not easily
calibrated after leaving the factory (at least the one I bought wasn't).
I will take a less precise instrument over one that is not accurate
any day. (Being able to measure that you're at 35-36ppt accurately is
better than thinking you're at 35.2 - 35.3 ppt when you're actually at
38ppt or worse because the instrument isn't calibrated properly.)

That said I do think my refractometer is difficult to read.. (The
"white" part is only a slightly lighter shade of blue than the blue
part. Maybe I just didn't get a very good one. :-) )

Eric
http://www.atreis.com/


Pszemol wrote:

> "Eric" > wrote in message ...
>
>>A measurement tool is more PRECISE if it can measure to a greater number
>>of significant digits. The Deep Six is a more precise measuring device.
>>
>>A measurement tool is more ACCURATE if it can come closer to the true
>>value of whatever it is you're measuring. The refractometer is more
>>accurate.
>>
>> From this, hopefully it's clear that it does no good to be more precise
>>if the instrument is not accurate. We use refractometers because they
>>are fairly accurate. Unfortunately, they are not very precise.
>
>
> :-)
> I guess I understand the difference between precision and accuracy, and it
> looks to me, a good accuracy is not worth anything without a good precision...
>
> A meter cannot be more accurate than 1ppt if it is not precise to a single ppt.
> Highly compressed scale on the refractometer hardly guarantee 1 ppt
> precission, which means the accuracy is not better than 1ppt as well...
>
> What refractometer gains on accuracy it looses on precission to swing arm.
> I would risk the statement a nicely calibrated (checked with the standard)
> swing arm could be more accurate than refractometer because of
> its greater precision :-)

[Pszemol]

"Eric" > wrote in message ...
> Terminology quibles aside, you're quite right. Unfortunately most swing
> arm devices don't seem to be well calibrated, and are not easily
> calibrated after leaving the factory (at least the one I bought wasn't).
> I will take a less precise instrument over one that is not accurate
> any day. (Being able to measure that you're at 35-36ppt accurately is
> better than thinking you're at 35.2 - 35.3 ppt when you're actually at
> 38ppt or worse because the instrument isn't calibrated properly.)

And this is the reason for the standards Randy was talking
on ReefCentral - you could use these standards to check
your swing arm and find out it gives you too high or too low
reading for 1ppt - later you can use this correction when
measuring water from your tank and periodicaly check the
swing arm for accuracy.

> That said I do think my refractometer is difficult to read.. (The
> "white" part is only a slightly lighter shade of blue than the blue
> part. Maybe I just didn't get a very good one. :-) )

Exactly my point. The scale is so compressed and the border
line not clear, it is difficult to get high accuracy with these guys.

[John]

I havent read the discussion on ReefCentral so I hope this isnt a repeat. Why
not use a common substance such as vinegar to test your hydrometer? I found
this on a webpage:
Malt vinegar is sold in four strengths designated 18, 20, 22, 24, the last
being proof vinegar, containing 6 % of acetic acid and having a specific
gravity of 1.019.
You could clean and check calibration in one step :)

Also, here's a chart of specific gravities of other different substances.
http://www.csgnetwork.com/sgvisc.html
~John

[Marc Levenson]

Try pointing the unit at a very bright light. I think you'll find the
white and blue are much more striking that way.

Marc


Eric wrote:
>
> That said I do think my refractometer is difficult to read.. (The
> "white" part is only a slightly lighter shade of blue than the blue
> part. Maybe I just didn't get a very good one. :-) )
>
> Eric
> http://www.atreis.com/
>

--
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[Pszemol]

Yes, it helps a little. Also, I tried to point the meter dirrectly at the bulb.
Anyway, the scale is so tight I can barelly see what ppt reading is it.
Maybe I need to check my vision ;-)

I have a dilema right now in my tank...
I have two different deep sixs showing 34ppt in my tank, but the
refractometer RHS-10ATC is at 39-40ppt mark. What to do now? :-)
I am not sure if my animals would feel healthy in 40ppt.

Ok, because refract is calibrated to NaCl not sea water, I should
subtract maybe 1.5 ppt from the reading => this gives me 38ppt...

But still, what to do with the rest, 4 ppt difference? :-)))
I know... I will start playing with the NaCl salt in my kitchen.

"Marc Levenson" > wrote in message m...
> Try pointing the unit at a very bright light. I think you'll find the
> white and blue are much more striking that way.
>
> Marc
>
>
> Eric wrote:
> >
> > That said I do think my refractometer is difficult to read.. (The
> > "white" part is only a slightly lighter shade of blue than the blue
> > part. Maybe I just didn't get a very good one. :-) )
> >
> > Eric
> > http://www.atreis.com/
> >
>
> --
> Personal Page: http://www.sparklingfloorservice.com/oanda/index.html
> Business Page: http://www.sparklingfloorservice.com
> Marine Hobbyist: http://www.melevsreef.com
>

[Marc Levenson]

Did you calibrate your unit with distilled water yet?

What is the sg reading on the opposite side of the scale?

Marc


Pszemol wrote:

> Yes, it helps a little. Also, I tried to point the meter dirrectly at the bulb.
> Anyway, the scale is so tight I can barelly see what ppt reading is it.
> Maybe I need to check my vision ;-)
>
> I have a dilema right now in my tank...
> I have two different deep sixs showing 34ppt in my tank, but the
> refractometer RHS-10ATC is at 39-40ppt mark. What to do now? :-)
> I am not sure if my animals would feel healthy in 40ppt.
>
> Ok, because refract is calibrated to NaCl not sea water, I should
> subtract maybe 1.5 ppt from the reading => this gives me 38ppt...
>
> But still, what to do with the rest, 4 ppt difference? :-)))
> I know... I will start playing with the NaCl salt in my kitchen.
>


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[Pszemol]

"Marc Levenson" > wrote in message m...
> Did you calibrate your unit with distilled water yet?

Yes, I did.
It was not at zero, so I used a screwdriver to make it point zero.

> What is the sg reading on the opposite side of the scale?

More than 1.030 sg.

Good my animals do not know that...
They probably panic and die if they knew how much salt they swim in ;-)

[Marc Levenson]

Well, I'm sure others like Boomer will have more to say, but basically I
just use the sg scale with my refractometer. And listen, when my sg is
1.l028 my zoanthids shrivel up and die... so take that 'with a grain of
salt'. :)

Marc


Pszemol wrote:
> "Marc Levenson" > wrote in message m...
>
>>Did you calibrate your unit with distilled water yet?
>
>
> Yes, I did.
> It was not at zero, so I used a screwdriver to make it point zero.
>
>
>>What is the sg reading on the opposite side of the scale?
>
>
> More than 1.030 sg.
>
> Good my animals do not know that...
> They probably panic and die if they knew how much salt they swim in ;-)

--
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[Pszemol]

My zoanthids, green polyps, brown polyps, Xenia Elongata, Pompom Xenia,
Tuxedo urchin, all 4 fish, all 5 shrimps, all snails and crabs - all these animals together
with lots of green hair algae :-) are doing great, so I do not think I have 1.030 :-))

Thinking something could be wrong with my refractometer I check it again
with my RO/DI water, and it was a little off zero, less than one division in plus...
So my readings are sligtly less than before but still much too high compared
to two deep six. I am going to check my water with somebody else refract
because it is starting to bother me... :-)

Maybe I will buy brand new Deep Six and if the third one will match other 2
I have, I will keep measuring with Deep Six and forget about other methods?

"Marc Levenson" > wrote in message ...
> Well, I'm sure others like Boomer will have more to say, but basically I
> just use the sg scale with my refractometer. And listen, when my sg is
> 1.l028 my zoanthids shrivel up and die... so take that 'with a grain of
> salt'. :)
>
> Marc
>
>
> Pszemol wrote:
> > "Marc Levenson" > wrote in message m...
> >
> >>Did you calibrate your unit with distilled water yet?
> >
> >
> > Yes, I did.
> > It was not at zero, so I used a screwdriver to make it point zero.
> >
> >
> >>What is the sg reading on the opposite side of the scale?
> >
> >
> > More than 1.030 sg.
> >
> > Good my animals do not know that...
> > They probably panic and die if they knew how much salt they swim in ;-)
>
> --
> Personal Page: http://www.sparklingfloorservice.com/oanda/index.html
> Business Page: http://www.sparklingfloorservice.com
> Marine Hobbyist: http://www.melevsreef.com
>

[Marc Levenson]

Boomer has brought this up before, but some refractometers don't match
35ppt to 1.026sg. That is misleading in itself. So yours reads 1.030
when you are at 35ppt? Mine isn't quite that high.

Marc


Pszemol wrote:
> My zoanthids, green polyps, brown polyps, Xenia Elongata, Pompom Xenia,
> Tuxedo urchin, all 4 fish, all 5 shrimps, all snails and crabs - all these animals together
> with lots of green hair algae :-) are doing great, so I do not think I have 1.030 :-))
>
> Thinking something could be wrong with my refractometer I check it again
> with my RO/DI water, and it was a little off zero, less than one division in plus...
> So my readings are sligtly less than before but still much too high compared
> to two deep six. I am going to check my water with somebody else refract
> because it is starting to bother me... :-)
>
> Maybe I will buy brand new Deep Six and if the third one will match other 2
> I have, I will keep measuring with Deep Six and forget about other methods?
>
> "Marc Levenson" > wrote in message ...
>
>>Well, I'm sure others like Boomer will have more to say, but basically I
>>just use the sg scale with my refractometer. And listen, when my sg is
>>1.l028 my zoanthids shrivel up and die... so take that 'with a grain of
>>salt'. :)
>>
>>Marc
>>
>>
>>Pszemol wrote:
>>
>>>"Marc Levenson" > wrote in message m...
>>>
>>>
>>>>Did you calibrate your unit with distilled water yet?
>>>
>>>
>>>Yes, I did.
>>>It was not at zero, so I used a screwdriver to make it point zero.
>>>
>>>
>>>
>>>>What is the sg reading on the opposite side of the scale?
>>>
>>>
>>>More than 1.030 sg.
>>>
>>>Good my animals do not know that...
>>>They probably panic and die if they knew how much salt they swim in ;-)
>>
>>--
>>Personal Page: http://www.sparklingfloorservice.com/oanda/index.html
>>Business Page: http://www.sparklingfloorservice.com
>>Marine Hobbyist: http://www.melevsreef.com
>>

--
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[Pszemol]

No, It was reading 1.030 when the edge was on 39-40ppt for my tank water.
When I get back home I will check what is the sg value for 35ppt....

"Marc Levenson" > wrote in message ...
> Boomer has brought this up before, but some refractometers don't match
> 35ppt to 1.026sg. That is misleading in itself. So yours reads 1.030
> when you are at 35ppt? Mine isn't quite that high.
>
> Marc
>
>
> Pszemol wrote:
> > My zoanthids, green polyps, brown polyps, Xenia Elongata, Pompom Xenia,
> > Tuxedo urchin, all 4 fish, all 5 shrimps, all snails and crabs - all these animals together
> > with lots of green hair algae :-) are doing great, so I do not think I have 1.030 :-))
> >
> > Thinking something could be wrong with my refractometer I check it again
> > with my RO/DI water, and it was a little off zero, less than one division in plus...
> > So my readings are sligtly less than before but still much too high compared
> > to two deep six. I am going to check my water with somebody else refract
> > because it is starting to bother me... :-)
> >
> > Maybe I will buy brand new Deep Six and if the third one will match other 2
> > I have, I will keep measuring with Deep Six and forget about other methods?
> >
> > "Marc Levenson" > wrote in message ...
> >
> >>Well, I'm sure others like Boomer will have more to say, but basically I
> >>just use the sg scale with my refractometer. And listen, when my sg is
> >>1.l028 my zoanthids shrivel up and die... so take that 'with a grain of
> >>salt'. :)
> >>
> >>Marc
> >>
> >>
> >>Pszemol wrote:
> >>
> >>>"Marc Levenson" > wrote in message m...
> >>>
> >>>
> >>>>Did you calibrate your unit with distilled water yet?
> >>>
> >>>
> >>>Yes, I did.
> >>>It was not at zero, so I used a screwdriver to make it point zero.
> >>>
> >>>
> >>>
> >>>>What is the sg reading on the opposite side of the scale?
> >>>
> >>>
> >>>More than 1.030 sg.
> >>>
> >>>Good my animals do not know that...
> >>>They probably panic and die if they knew how much salt they swim in ;-)
> >>
> >>--
> >>Personal Page: http://www.sparklingfloorservice.com/oanda/index.html
> >>Business Page: http://www.sparklingfloorservice.com
> >>Marine Hobbyist: http://www.melevsreef.com
> >>
>
> --
> Personal Page: http://www.sparklingfloorservice.com/oanda/index.html
> Business Page: http://www.sparklingfloorservice.com
> Marine Hobbyist: http://www.melevsreef.com
>

[Boomer]

If the meter is a std Sg/Salinity meter the exact matching numbers should be 35 pp =
1.0264, which is a density of 1.0237. Those refracts are hard to read and split numbers

On another note Marc "1.l028", yes they would be dead. Ok, just teasing I know it is typo.
I have done it myself enough times. Just giving you **** :-)

Pszemol

There is nothing wrong with using a Deep-Six, although I would much rather use a Seatest.
Either needs to be checked for accuracy. Once done so they are quite accurate and precise.
I use to check mine with a conductivity, meter. I was lucky, my SeaTest read exactly 35
ppt when the conductivity meter read 53.0 mS. My meter went to 100,000 uS and my
calibration solution was 58.64 mS (53,640 uS). NSW is 53.025 mS or 53,025 uS. Then I would
use the SeaTest. We really don't need to get that accurate, a refract is just fine once
corrected for offset.


--
Boomer

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If You See Me Running You Better Catch-Up
"Marc Levenson" > wrote in message
...
: Boomer has brought this up before, but some refractometers don't match
: 35ppt to 1.026sg. That is misleading in itself. So yours reads 1.030
: when you are at 35ppt? Mine isn't quite that high.
:
: Marc
:
:
: Pszemol wrote:
: > My zoanthids, green polyps, brown polyps, Xenia Elongata, Pompom Xenia,
: > Tuxedo urchin, all 4 fish, all 5 shrimps, all snails and crabs - all these animals
together
: > with lots of green hair algae :-) are doing great, so I do not think I have 1.030 :-))
: >
: > Thinking something could be wrong with my refractometer I check it again
: > with my RO/DI water, and it was a little off zero, less than one division in plus...
: > So my readings are sligtly less than before but still much too high compared
: > to two deep six. I am going to check my water with somebody else refract
: > because it is starting to bother me... :-)
: >
: > Maybe I will buy brand new Deep Six and if the third one will match other 2
: > I have, I will keep measuring with Deep Six and forget about other methods?
: >
: > "Marc Levenson" > wrote in message
...
: >
: >>Well, I'm sure others like Boomer will have more to say, but basically I
: >>just use the sg scale with my refractometer. And listen, when my sg is
: >>1.l028 my zoanthids shrivel up and die... so take that 'with a grain of
: >>salt'. :)
: >>
: >>Marc
: >>
: >>
: >>Pszemol wrote:
: >>
: >>>"Marc Levenson" > wrote in message
m...
: >>>
: >>>
: >>>>Did you calibrate your unit with distilled water yet?
: >>>
: >>>
: >>>Yes, I did.
: >>>It was not at zero, so I used a screwdriver to make it point zero.
: >>>
: >>>
: >>>
: >>>>What is the sg reading on the opposite side of the scale?
: >>>
: >>>
: >>>More than 1.030 sg.
: >>>
: >>>Good my animals do not know that...
: >>>They probably panic and die if they knew how much salt they swim in ;-)
: >>
: >>--
: >>Personal Page: http://www.sparklingfloorservice.com/oanda/index.html
: >>Business Page: http://www.sparklingfloorservice.com
: >>Marine Hobbyist: http://www.melevsreef.com
: >>
:
: --
: Personal Page: http://www.sparklingfloorservice.com/oanda/index.html
: Business Page: http://www.sparklingfloorservice.com
: Marine Hobbyist: http://www.melevsreef.com
:

[Pszemol]

"Boomer" > wrote in message ...
> If the meter is a std Sg/Salinity meter the exact matching numbers should be 35 pp =
> 1.0264, which is a density of 1.0237. Those refracts are hard to read and split numbers

This is what I see for mine - just checked a moment ago: 35ppt level is about at 1.027 SG.
But it is really hard to see because the scale is too tight for my poor vision...
Yes, I wear glasses :-) I guess, refractometer is not a good tool for me :-))

> Pszemol
>
> There is nothing wrong with using a Deep-Six, although I would much rather use a Seatest.

I noticed them - they look kind of big, but I guess this makes them more accurate.
I like mine because of the way how I make the sampling: by dipping it stright down.

> Either needs to be checked for accuracy. Once done so they are quite accurate and precise.

I got the third one today :-)) I did not have a chance to check the reading on that one.
Two I have are pretty repeatable: both are RIGHT at 34ppt in my tank water...

> I use to check mine with a conductivity, meter. I was lucky, my SeaTest read exactly 35
> ppt when the conductivity meter read 53.0 mS. My meter went to 100,000 uS and my
> calibration solution was 58.64 mS (53,640 uS). NSW is 53.025 mS or 53,025 uS.

I do not quite get this part - why your meter went to 100mS in 58mS standard??
Was it broken?

> Then I would use the SeaTest. We really don't need to get that accurate,
> a refract is just fine once corrected for offset.

Is there any particular reason you prefer SeaTesT over Deep Six?

[Boomer]

"I do not quite get this part - why your meter went to 100mS in 58mS standard??
Was it broken?"

No, my meter has 3 scales on it for conductivity. I should have said my meter goes to
100mS or has a limit to 100mS NSW is 53 mS, the calibration solution I used is 58mS. I
said "went to", out of habit, as it is past tense, as the probe does not work anymore. I
getting it fixed now.


--
Boomer

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If You See Me Running You Better Catch-Up
"Pszemol" > wrote in message ...
: "Boomer" > wrote in message
...
: > If the meter is a std Sg/Salinity meter the exact matching numbers should be 35 pp =
: > 1.0264, which is a density of 1.0237. Those refracts are hard to read and split
numbers
:
: This is what I see for mine - just checked a moment ago: 35ppt level is about at 1.027
SG.
: But it is really hard to see because the scale is too tight for my poor vision...
: Yes, I wear glasses :-) I guess, refractometer is not a good tool for me :-))
:
: > Pszemol
: >
: > There is nothing wrong with using a Deep-Six, although I would much rather use a
Seatest.
:
: I noticed them - they look kind of big, but I guess this makes them more accurate.
: I like mine because of the way how I make the sampling: by dipping it stright down.
:
: > Either needs to be checked for accuracy. Once done so they are quite accurate and
precise.
:
: I got the third one today :-)) I did not have a chance to check the reading on that one.
: Two I have are pretty repeatable: both are RIGHT at 34ppt in my tank water...
:
: > I use to check mine with a conductivity, meter. I was lucky, my SeaTest read exactly
35
: > ppt when the conductivity meter read 53.0 mS. My meter went to 100,000 uS and my
: > calibration solution was 58.64 mS (53,640 uS). NSW is 53.025 mS or 53,025 uS.
:
: I do not quite get this part - why your meter went to 100mS in 58mS standard??
: Was it broken?
:
: > Then I would use the SeaTest. We really don't need to get that accurate,
: > a refract is just fine once corrected for offset.
:
: Is there any particular reason you prefer SeaTesT over Deep Six?

[Pszemol]

"Boomer" > wrote in message ...
> "I do not quite get this part - why your meter went to 100mS in 58mS standard??
> Was it broken?"
>
> No, my meter has 3 scales on it for conductivity. I should have said my meter goes to
> 100mS or has a limit to 100mS NSW is 53 mS, the calibration solution I used is 58mS. I
> said "went to", out of habit, as it is past tense, as the probe does not work anymore. I
> getting it fixed now.

Now it is clear - thanks.

[Pszemol]

"Pszemol" > wrote in message ...
> Maybe I will buy brand new Deep Six and if the third one will match other 2
> I have, I will keep measuring with Deep Six and forget about other methods?

I have now three Deep Six hydrometers showing exactly 34ppt.
All three together. Pretty good instrument.