Red Sea Mg Ca Kh frustration
 

I’ve been using this test kit for the last couple of weeks and I really do find it inconsistent in results and very fiddly to use. The Mg I’ve followed to the rule. 15 secs between drops, 1 minute for the 5 drops getting a result of 1500. Re do the test but for 20 secs and I get a different result, this time 1400. When I compare to the likes of JBL and Salifert it’s always 50:60 points higher. Ca not quite so bad but is always 25 lower than Salifert and 40 higher than JBL. KH I have to run 3 tests as this also is inconsistent by giving high results. I have to do 3 tests for each just to get a repeat result. Very disappointing!!!!! and is affecting my dosing regime because the results cannot be relied upon. Does anyone else have this experience.


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Moved to this forum as more on topic here. I can move it to the Chemistry Forum if that works better.

I notice some inconsistency with my alk test. The first test often reads a higher alk than subsequent tests. This test procedure is very simple so there must be an explanation. I wonder if something in the tiny amount of residual water in the vial is affecting the test results. I do rinse the vial very well with rodi after each test but then put the vial away wet.

The way you describe your mg results, well it makes sense that you change the test procedure and it produces different results. But the alk test is so straightforward that the inconsistency is strange to me as well.


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i dont have a problem with my, consistant results with my hanna checker.

mine*

I’ve extended the 15 sec mix on MG1 to 30 sec mix and interestingly I’m getting lower results that now make sense. On the face of it, it looks like the mixing isn’t long enough to dissolve and mix the ingredients. The Red Sea is now lower than Salifert by 30 points.


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I didn’t think you could get a Hanna checker for Mg?


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Check with Red Sea, my LFS reported the same problem and found there was a 'bad batch' at some point and they sent new kits free of charge. You do need to locate the lot numbers on the bottles for their info.

Hold on. If you're frustrated with this brand of kit, and you have other brands available (since you listed testing against them), why not just toss these and use the other ones? Why continue to troubleshoot?

My problem was trying to select the test kit that provided the most accurate result. With such a big gap between kits it’s difficult to understand which one is correct .


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I don't think absolute value accuracy is the most important thing for these parameters. Mg at 1400 versus 1450 isn't going to change anything. Consistency and ease of use are definitely more important. I'd pick the kit you find easiest to get reproducible results with.

Make sure your chemicals are not out of date. My Hannah Alk checker was giving me goofy readings and the chemical fluid was only 1 month out of date.