Saltmix Parameters bring on the test results

[Randy Holmes-Farley]

The above tests are Aquaforest? Curious to see the Sulphur/moly/barium that off from setpoint.. I believe that limited amount of Sulphur would surely hinder anaerobic denitrification?

It's very strange if accurate, and I wouldn't use the mix if sulfate was that low.

The sulfur in question is present as sulfate. There is still a lot of sulfate available to convert into hydrogen sulfide if nitrate is depleted under anaerobic conditions (denitrification involving sulfate), but sulfate plays no particular role in denitrification reactions involving nitrate and organics, which is what more often happens in reef tanks.

 

[jason2459]

It's very strange if accurate, and I wouldn't use the mix if sulfate was that low.

The sulfur in question is present as sulfate. There is still a lot of sulfate available to convert into hydrogen sulfide if nitrate is depleted under anaerobic conditions (denitrification involving sulfate), but sulfate plays no particular role in denitrification reactions involving nitrate and organics, which is what more often happens in reef tanks.

The Probiotic version provided by Tompot on RC showed a lot of Al. Waiting for my results.

Possible QC issue?

 

[Randy Holmes-Farley]

I can't imagine anyone would intentionally make a salt that low in a major ion.

 

[jason2459]

Agree and I can't imagine Triton's test being that far off even for those that are skeptical of their results.

 

[jason2459]

RedSea Coral Pro

Did this last night but finally getting a chance to post the number.

What they say

Instructions I showed inaccurate

And what I get at 35ppt

Ca: 430
Alk: 12.16
Mg: 1425

 

[jason2459]

@Randy Holmes-Farley
@JimWelsh

Curiosities

The spreadsheet to calculate the salinity level from the Triton results is in PSU

I've noticed in some salt mixes that calculated number to be lower then the salinity I've measures in PPT via my refractometer. But sometimes very close. I think there's been one instance it was higher.

Would the variations in element ratios effect the differences of PSU calculated vs PPT via refractometer?

 

[jason2459]

Looking at page 1 IO and RC were very close to spot on.

Where as this latest results from aquaforest the calculated PSU was lower then the salinity measured.

 

[JimWelsh]

@Randy Holmes-Farley
@JimWelsh

Curiosities

The spreadsheet to calculate thr salinity level from the Triton results is in PSU

I've noticed in some salt mixes that calculated number to be lower then the salinity I've measures in PPT via my refractometer. But sometimes very close. I think there's been one instance it was higher.

Would the variations in element ratios effect the differences of PSU calculated vs PPT via refractometer?

As I read it, there are basically two questions here:

(1) Would variations in ionic ratios affect the refractometer reading?
(2) Is there a difference between the PSU and PPT scales?

If I misunderstand what you are asking, please feel free to correct me.

Regarding #1, I've done some work to investigate the effect of various ions on the refractive index of the solution. This ended up being much more complex than I expected, but the over-simplified answer is that "yes", different solutions with the same salinity (defined as g/kg of total dissolved salts), but different ionic ratios, may very well have different refractive indexes. Admittedly, the effect is small, but it does exist. The most significant imbalance is Mg, which contributes a relatively low refractive index, and will make the sample's salinity read slightly lower when Mg is elevated, and slightly higher when Mg is lower than normal. I don't have numbers handy to quantify this effect, but it is rather small.

Regarding #2, how my spreadsheet does these calculations is described on the "Introduction" tab. In short, it calculates the estimated g/kg of the total salts in the sample. It then compares that to the total amount of salts that are in seawater with S=35 according the the PSS-78 standard, which is 35.16504 g/kg. So, if the estimated total salts is 35.16504 g/kg exactly, then the spreadsheet will call the salinity "35.00". If the total salts are higher or lower than 35.16504 g/kg, then the salinity will be shown as higher or lower, proportionally. If you are calibrating your refractometer according to Randy's article found here http://www.reefkeeping.com/issues/2004-06/rhf/ then you are calibrating it to the PSU scale, and not PPT. Otherwise the potential in scale differences depends upon what standard you are calibrating your refractometer with. One note: The "Temperature" input of my spreadsheet is intended to be the temperature *at which Triton is taking the sample and against which the results are being reported*, and NOT the tank temperature. I didn't make that clear in the "Introduction".

I hope this helps!

 

[JimWelsh]

Where as this latest results from aquaforest the calculated PSU was lower then the salinity measured.

Well, now that I look at the Aquaforest results, that suspiciously low S value would definitely cause a low salinity calculation. I suspect that the reported S value may be erroneous. Please remember that my spreadsheet is at the mercy of Triton's accuracy!

 

[jason2459]

Thanks Jim. Yes, those were my basic questions. I also notice on my Milwaukee digital refractometer that when at 35PPT the s.g. is at 1.026 and PSU is 34.


I have sent an email to Triton stating those results seem to be in error and waiting for a response.

 

[jason2459]

Oh, and yes I've been calibrating via Randy's article using Pickling salt.

Since around May
https://www.reef2reef.com/threads/does-your-calibration-solution-need-calibrated.250133/

 

[jason2459]

Triton's response and being a major element in seawater I assume even if it's not accurate the result isn't that far off from the actual levels.

 

[Randy Holmes-Farley]

It might be an error like a typo and not a test error.

 

[jason2459]

It might be an error like a typo and not a test error.

They confirmed in that email they most definitely read S that low. Even if not spot on it's most likely close enough.

 

[jason2459]

Aquaforest reached out to me and offered to test the salt via their ICP-OES equipment. I'm just waiting to hear back how much of the dry salt to send them. It will be to Polland.

Pretty cool they actively reached out to me which was nice. I'll send them both the probiotic and reef blend to see how their testing lines up with Triton's.

 

[jason2459]

So, I underestimated what AquaForest is offering to do for me. They are willing to test any saltmix I want to send them. That is a very generous offer and plan to take them up on that offer.

Of course its not exactly a 3rd party so will not post the mix I'm testing on here before getting results back.

 

[Randy Holmes-Farley]

Yes, the only useful way is blind.

 

[jason2459]

Speaking of which...

Aquaforest Probiotic Reef Salt

Supposed to be QC'd to

Keep in mind those are at 33ppt.

Tried to match the salinity mark I had for the Reef blend to get as close of a comparison as I could between the two.

So, at a low 35ppt
Ca: 420
Alk: 7.04
Mg: 1485

And here's Triton's results.

Sulfur not nearly as low and matches tompot's triton results for probiotic mix but still lower then many of the other brands.

Salinity I tried to match to the reef mix and Triton's test results calculate higher at 33.97PSU. Could be the higher S content or just mixed higher even though I did try matching.

Barium is still high with this mix as well. I don't know if this is bad or not but good if you need to take your fish in for a GI scan I guess.

Al thankfully did not match tompot's triton results which were very high.

Li is pretty low for both aquaforest mixes and tropic marine pro. For anyone looking for a low Li salt for one reason or another.

 

[jason2459]

RedSea Coral Pro

Did this last night but finally getting a chance to post the number.

What they say

Instructions I showed inaccurate

And what I get at 35ppt

Ca: 430
Alk: 12.16
Mg: 1425

And Triton's results

Elevated amounts of Mn and I but really pretty good numbers. Alk is on the high side but that could be good to help supplement that too in small water changes.

Salinity is estimated at just over 33PSU.

I'm fnding this interesting. Going to go back to my normal mark I use for 35ppt and also weigh back out a 35ppt standard but from Jim Randy's recipe is to PSU. So, I guess I should specify that and will line up with the calculated estimated values.

Next mix should reflect that.

I have a batch of 50 sterile 50ml vials on order and waiting to get those in to start sending sample over to Aquaforest.

 

[jason2459]

I got 50 50ml sterile vials in today to send first some RODI and then some samples of different salt mixes. But looks like I need some new DI again. I'll get it ordered tonight.