Na

[gpwdr]

My tank is crashing and I'm looking for reasons why.
Does the Na reading in our lab results indicate the salinity level as to the refractometer?

Is there a difference between calibration solutions for the refractometer and the neptune salinity probe?
My tank is showing 35 with the neptune and 40 with the refractometer?
I’m going to buy some calibration fluids buy not sure what to get?

 

[gpwdr]

 

[chipmunkofdoom2]

Calibration fluids are not always universal. In some cases, standards are made to be seawater mimics, so they should read about seawater values no matter what tool you use. However, this is not always the case. Some standards are designed for a specific type of measurement device only.

A refractometer measures refractive index, or how light travels through a fluid. Salinity probes, by contrast, usually measure conductivity. In other words, they measure how a sample conducts electricity. A calibration standard that causes a refractometer to read 1.0264 SG will NOT necessarily cause a conductivity probe to register a conductivity of 53.0 mS/cm. Randy's article on calibration standards gives a different recipe for refractometers as opposed to conductivity meters (as well as a third recipe for hydrometers).

I would not blame overall salinity for your problems just yet. Your salinity is likely high, as your calcium and magnesium are about 64% and 20% higher than natural seawater, respecitvely. But, you so far have two measurements of salinity, a conductivity probe and a refractometer, and neither agree. I would personally make some of Randy's DIY refractive index standard and measure your salinity after calibrating your refractometer.

 

[HolisticBear]

My tank is crashing and I'm looking for reasons why.
Does the Na reading in our lab results indicate the salinity level as to the refractometer?

Is there a difference between calibration solutions for the refractometer and the neptune salinity probe?
My tank is showing 35 with the neptune and 40 with the refractometer?
I’m going to buy some calibration fluids buy not sure what to get?

Salinty is a mix of all the ions, some contribute more than others. This calculator will give you a rough idea from a report:

https://monrecifamoi.saulme.fr/salinite/elements_compute_salinity.php

Calibration solutions vary, they need to be shaken before each use (refractometer solution). Electrical interference can mess with probe readings.

 

[Want2BS8ed]

My tank is crashing and I'm looking for reasons why.
Does the Na reading in our lab results indicate the salinity level as to the refractometer?

Is there a difference between calibration solutions for the refractometer and the neptune salinity probe?
My tank is showing 35 with the neptune and 40 with the refractometer?
I’m going to buy some calibration fluids buy not sure what to get?

Oh no Gene! Keep us posted on what you discover. I have always admired your tank and appreciated our past correspondence on lighting... you are obviously a talented aquarist, so I hope you find a solution swiftly.

Do a quick search on Randy Holmes-Farley. If memory serves he provided a DIY formula for refractometer calibration fluids using table salt.

Fingers crossed from here.

M

EDIT: Gene here is Randy's original article:
http://www.reefkeeping.com/issues/2004-06/rhf/

 

[Motts]

isn't there a online salinity calculator were you can upload your icp results?

 

[gpwdr]

After talking to Tim I think throwing out all the algae in the refugium caused an NO3 spike. I 'll know more from the test sent to Triton. I'll never do that again.
A beautiful blue Stylophora spp. bleached out. and a huge green slimer turned completely brown. Most of the corals started tissue recession.
I'm going to do a 25 gallon water change on the 145 gallon system and wait for the test to come back.

 

[gpwdr]

isn't there a online salinity calculator were you can upload your icp results?

I no longer think its the salinity. I had this Triton setup going fo almost 4 years with no problem.

 

[Joe Batt]

The Neptune salinity probe never seems to be accurate for me, and seems to cause problems for many. I use a Milwaukee refractometer and then just use the Neptune probe to let me judge changes around that.