Salt the question, once again!

[Scooterman]

Curt, I wonder if that same test was run now, if it would be the same?

 

[Craig Manoukian]

Good question Scott, you must have been reading my mind!

 

[Scooterman]

Bump, the question still goes unanswered, would the test results be the same today, can you justify testing a series of salt mixes, then allow everyone to think that is it? The reason I bring this up is because of the inconsistency problems we face with every manufacturer at any given time. I believe the phosphate test would show differently if these test were done today or any day at random.

 

[tankgirl]

Hi Curt & Mike, Thanks, guys!
Nice link, Curt. I wonder if Coralife has changed their formula since that study (looks like it was done 5 years ago)? Cause I test for phosphate every week, and it's never been more than 0.03 ppm (and is usually zero reading). I was using NSW until I discovered it was horrendously high in phosphates.

Can anyone translate the umoles/kg for me, into ppm? Isn't a umole something like a millionth of a mole (which is Avogadro's number of molecules, I think)? I'm wondering if all those numbers in that chart are vastly tiny. Just curious about it.

The contaminants are a concern. I always test pH of freshly made up SW, and get around 8.1 on that. But, I notice in that link that, after atmospheric equilibration, that Coralife is lower than most of the other mixes - that it's only higher when first mixed.

 

[cwcross]

Test precision is a good question here. Somebody should do a series of 5 tests on a single batch of salt over a 5 day period and calculate an average value and the standard deviation. Without understanding the precision of the test itself, it is impossible to understand the variability between different salts. Ideally 5 diffrent people should do a test on a single salt solution. That way we get test precision and worker precision...this is called a gage R&R (repeatability and reproducibility). This should always be a starting point to compare data from a statisitical perspective.....C

 

[tankgirl]

Hi Collin,
Do you mean 5 phosphate tests? Would phosphate vary over the 5 days, or is that just to get an avg.? I'd be willing to do that.

 

[cwcross]

Hi Collin,
Do you mean 5 phosphate tests? Would phosphate vary over the 5 days, or is that just to get an avg.? I'd be willing to do that.

I mean 5 tests on the exact same standard batch of salt or aquarium water or both. take a sample, run a phosphate test on it 5 times in 5 days. That way we can see the variability of the test itself. If the test has a 50% error margin, how can we use it to validly compare salts that differ by less than 50% relative? If it is only 10% error, on the other hand, and salts differ by more than 10% then we can say that they are statistically different outside the error of the test. This is standard experimental procedure.

I personally don't care myself, but if one is using a test to compare things, they should no how accurate the test is in comparison to the differences they are trying to compare. The standard deviation of a series of tests can be used to understand how precise the test is.

Sincerely...Collin

 

[mojoreef]

Bump, the question still goes unanswered, would the test results be the same today

Hi Scotty, perhaps I could answer it a bit. Formulation rarely changes on mass. The vast bulk of salt make up is basically a few elements, Chloride and Sodium taking up the vast majority of what salt is. These elements are purchased in bulk and are of a normal grade. Now some salts use synthetic elements and some collect reclaimed, both have pros and cons but the underlying base is Normal grade. With normal grade your going to get impurities, they might vary from batch to batch and year to year, but a constant can be seen. Now as for the balance of the elements which only consitutes a very tiny portion of the mix you might see some changes in formulation and in inconsistancy, but at best it is going to be minor (unless it is a mistake).
When it comes to nutrients in ASW if you look at the testing you will see that they either contain P or N. Example would be TM it contains higher levels of P but very low levels of N. where as IO contains very low levels of P but higher levels of N. As I have said before it is really a pick you poisen type of thing. Every salt has its pros and cons, so it is a tough arguement to make logically.
Most metals and impurities in ASW are bound up by universal binders in the salt mix itself. these bonds hold until it is released by bacteria. From their bacteria, chelatons, ligands and so on ake over and bind it in the tank. That is one of the reasons Dr. Rons salt test is mostly smoke.
On the amount of alk, cal and Mag in the mix. Yes it would be nice, but really doesnt pertain alot. The creatures that we keep (from corals to corraline algae) use all three elements and will begin to reduce those levels as soon as the water is in the tank. So it may be to proper level in the mix bucket, but an hour later its already lowered. So IMHO not a huge selling point, but doesnt hurt.

anyway enough blabbering


Mike

 

[Scooterman]

So basically your saying, pick your poison, adjust your major elements as necessary, & go with it! Right?

 

[tankgirl]

I mean 5 tests on the exact same standard batch of salt or aquarium water or both. take a sample, run a phosphate test on it 5 times in 5 days. That way we can see the variability of the test itself. Collin

Thanks, Collin. I see what you mean now. An interesting test, I'll try that. Can you answer my question about the umoles, whether that is millionths of a mole, btw? I'm curious about that chart link Curt posted - how meaningful those figures are to us. And how those figures translate into ppm or mg/l. Thanks!

 

[Scooterman]

TG, here is your conversion utility, can help on the rest sorry.

http://www.onlineconversion.com/flow_rate.htm

 

[tankgirl]

Thanks, Scott!

Yeesh! Bingman said (in that article), "To convert these values to parts per million (ppm) multiply the concentration in millimolar by the molar mass of the element. Multiplying the values in micromoles per kilogram by the molar mass gives parts per billion (ppb). "

The molar mass of Phosphorus is 30.97 g/mol (am rounding up to 31 g/mol)

Bingman said there were 0.95 umoles/kg of inorganic phosphorus so
0.95 x 31 = 29 ppb or 0.003 ppm.

That would read zero on a Salifert test kit. The smallest reading on the test kit is 10 times that much. The cooresponding organic phosphorus would be even smaller.

Right?

 

[Scooterman]

That's the difference between a hobby test kit & a lab LOL!

 

[zeltar]

Thanks, Scott!

Yeesh! Bingman said (in that article), "To convert these values to parts per million (ppm) multiply the concentration in millimolar by the molar mass of the element. Multiplying the values in micromoles per kilogram by the molar mass gives parts per billion (ppb). "

The molar mass of Phosphorus is 30.97 g/mol (am rounding up to 31 g/mol)

Bingman said there were 0.95 umoles/kg of inorganic phosphorus so
0.95 x 31 = 29 ppb or 0.003 ppm.

That would read zero on a Salifert test kit. The smallest reading on the test kit is 10 times that much. The cooresponding organic phosphorus would be even smaller.

Right?

Yeah, whatever she said!!!!! lol

 

[cwcross]

It is likely that this method is not quite right. Inorganic phosphorous is not P, by itself. Typically, when measuring inorganic Phosphorous, the number is reported "as PO4". That would mean that the molecular weight for PO4 should be used instead of P by itself. However, it is not specified that I saw so I may be incorrect. Other than that the conversion seems correct. Accounting for PO4 would only change the number by about a factor of 3 or so though, because oxygen has a molecular weight of 16 basically so PO4 would have a MW of approx 64+31 roughly..=95 instead of 31 or whatever.

Collin

 

[tankgirl]

Hi Collin,
Yeah, that was a little confusing to me - that he stated the results in phosphorus rather than phosphate.

According to Randy Holmes-Farley, in this article:
http://www.advancedaquarist.com/issues/sept2002/chem.htm
The avg. concentration of phosphate in NSW (near the surface) is 0.005 ppm.

Both those concentrations (in Coralife and in NSW) are well below the concentration of phosphate added to the tank in a single feeding. So, I'm not convinced that I should jump to change salt based on the phosphates, at least.

 

[cwcross]

Yea, I agree. I don't think phosphate concentrations would be a big driver to change salts. I think most are pretty low in P. I think consistency and ease of use are the biggest drivers for a salt...C

Hi Collin,
Yeah, that was a little confusing to me - that he stated the results in phosphorus rather than phosphate.

According to Randy Holmes-Farley, in this article:
http://www.advancedaquarist.com/issues/sept2002/chem.htm
The avg. concentration of phosphate in NSW (near the surface) is 0.005 ppm.

Both those concentrations (in Coralife and in NSW) are well below the concentration of phosphate added to the tank in a single feeding. So, I'm not convinced that I should jump to change salt based on the phosphates, at least.

 

[MINIATUS]

Min a mix of 6 parts baking soda with 1 part washin soda will give you a alkalinity buffer. Using washing soda alone will raise your Ph but will not affect you alk.
The method of making the alkalinity buffer is to mix as stated above and then place on a cookie sheet and place in the oven at 200F for about two hours. then remove and bottle it up for use.

Mike

Mike 2 questions cookie sheet , any kind prefered , is teflon better than steel or alumium. My concern is alumium when heated with it do something to the mix.
I finally found washing soda up here and I dont think it has any perfumes added. see pic. MINIATUS

 

[CarlaW]

Miniatus,
That is the one you want.

 

[MINIATUS]

One more question on this mix. I was just looking at a small container of Kent Marine pH buffer and it mentions borate salts. What are they and where does this fit into the mixture.

MINIATUS :?: