Korallen Zucht - Reefers Best Premium Coral Reef Salt (20kg) KH, Ca, Mg variations

[androal]

I recently bought some of this salt from BRS (they've been offering it at 25% off for some time now...)

When I mix it up at a specific gravity of 1.26, I consistently get some pretty different results from what I have read that other's have gotten. This is what I consistently get on my Elos test kit using this salt mix (brand new kits)

CA 380
KH 12
MAG 1150

This is after dry mixing the salt, and also using the entire batch, which should eliminate the whole "settling" debate right? Also used two separate 20kg boxes, and got same results from both boxes.

This poses several problems/questions for me:

1- Why are there such significant variations in peoples published results from this salt mix? Especially KH levels. KH seems to be one of the more simple tests to run, which would leave me to believe that the numbers people are floating around are true - for them. Yet there are alarmingly vast discrepancies from various posts out there on peoples experiences with this salt mix. Are the large variations coming from the users testing techniques/kits, or is it that the manufacturers mixes are varied due to the small-batch manufacturing I've read about?

2- While the test kits seem pretty straight forward, I have had some issues with the way each number is derived using the Elos test kits I have. My understanding is that the other test kits (Red Sea, Salifert) use basically the same methodology and thus have similar problems with accuracy/user error?

The Ca test kit I use from Elos is accurate to 10mg, but there is always a question as to when it "turns" from one color to the other. I.E. is it drop 9 or drop 10 that it turns fully from one color to the next. I usually have it turn partially at one drop point, and then more at the next drop, and not completely until the third drop.

 

[bertoni]

I don't know what kind of tolerances the salt manufacturers tolerate. We do see a lot of reports of varying parameters. Some of that might be due to testing problems, which also show up frequently.

I would be careful about assuming that all test kits have the same accuracy, although they all might be close enough. Also, test kits also sometimes show up in bad batches. Generally, a titration kit is going to be ±1 drop, as you noted. The differences in salt batches seem to be bigger than that, though on occasion.

 

[Charlene]

I've never tried it but I've read it needs to be thoroughly pre-mixed before you put it in your water as either settling can occur or the manufacturer does not pre mix it. Failure to do this will result in uneven batches.