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07/07/2012, 10:23 AM | #1 |
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Different Mg readings - Salifert vs Red Sea Pro
Not that this is a huge difference, just wondering which is best to go with.
I get about a 80-100ppm difference between my Salifert and Red Sea Pro Mg testkits. This morning reading for example: Salifert = 1280 RSP = 1380 Should I take 1/2 the difference? Or is one more reliable than the other normally?
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450g Mixed SPS/LPS Reef (MH/T5/VHO) |
07/07/2012, 10:29 AM | #2 |
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It could also be operator error, a known variable in any test. Not a negative thing, it's just something to expect and acknowlege.
If I am truly curious, and I most often am , I would do 3 separate tests each for Salifert and Red Sea Pro, all in one sitting, and then compare.
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Anything I post is just an opinion. One of many in this hobby. Believe and follow at your own risk of rapid and complete annihilation of all life in your tank :) Current Tank Info: Incept 3/2010, 150 RR, 50g sump, 20g fuge, 150w 15K MH x3, T5 actinics x8, moonlight LED x6, 1400gph return, Koralia 1400 x4, 300 g skimmer, 4 tangs, 2 mandarins, 2 perc, 6 line, 3 cardinals, 2 firefish, SPS, LPS, zoas, palys, shrooms, clam |
07/07/2012, 10:38 AM | #3 |
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Possibly, but it has been doing this for some time now, consistently different in reading. Even consistent when the reading was much higher. Used to get 1580 vs 1500.
But will test again to make sure. I have always hated the droppers with the Salifert testkits as always question the consistency of each drop and sometimes I suspect that 2 drops came through at the same time. Wish they would get higher quality ones. If I dose to bring Mg back to 1450 using the average of the two, then it is possible Mg is actually either 1500 or 1400. Either way should be fine right?
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450g Mixed SPS/LPS Reef (MH/T5/VHO) |
07/07/2012, 10:40 AM | #4 |
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Get a solution with a known magnesium level and check with both kits to see which one is right.
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David Current Tank: Undergoing reconstruction... |
07/07/2012, 10:47 AM | #5 | |
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Quote:
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07/07/2012, 11:39 AM | #6 |
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Well tried with 1/2 gallon + 1 TBSP epsom salt but neither result looked right... probably need to try with a larger measurement. Will do another time.
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450g Mixed SPS/LPS Reef (MH/T5/VHO) |
07/07/2012, 12:32 PM | #7 |
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I just ran the tests on my tank 3 times each. Each test was within 20ppm of the last test.
Salifert - Averaged 1220 (noting 60 less than the test I did originally) RSP - Averaged 1340 (40 less than the original test) So with that there is a 120ppm difference. Both are fairly new. <1 Year on the Salifert (exp listed of 6/2013), and <3 months on the RSP.
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450g Mixed SPS/LPS Reef (MH/T5/VHO) |
07/07/2012, 12:59 PM | #8 | ||
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From a chemist or perfectionist standpoint, it kinda sucks to have such a widely disparate result between two "precision" tests. Guess anything more precise may be too expensive for a hobbyst, though.
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Anything I post is just an opinion. One of many in this hobby. Believe and follow at your own risk of rapid and complete annihilation of all life in your tank :) Current Tank Info: Incept 3/2010, 150 RR, 50g sump, 20g fuge, 150w 15K MH x3, T5 actinics x8, moonlight LED x6, 1400gph return, Koralia 1400 x4, 300 g skimmer, 4 tangs, 2 mandarins, 2 perc, 6 line, 3 cardinals, 2 firefish, SPS, LPS, zoas, palys, shrooms, clam |
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07/08/2012, 07:14 AM | #9 | |
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