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02/28/2015, 08:48 PM | #1 |
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Magnesium levels
So I have been dosing two BRS two part dosing supplement. 50 mis/day of Ca and 30 mls of alkalinity. My Ca remains between 420 and 440 depending on the day. Alkalinity is about 130-140 ppm (7-8 dkh). I am getting coraline algae growth but have not added any magnesium and that pretty much has remained constant over two months. about 1400 ppm. Any reason I am not seeing this decrease yet? I have some SPS corals as well for the last three weeks and they are doing fine. I don't expect to notice any growth in three weeks. Phosphate 0.00 (hanna test kit), nitrates 0 (red sea). Mg test kit is red sea, alkalinity (hanna), Ca (Hanna). No decrease at all in Mg since the last water change two weeks ago.
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02/28/2015, 08:59 PM | #2 |
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None of my tanks ever consumed enough magnesium that I needed to supplement it. The consumption ratio of magnesium to calcium tends to be very small, although it is variable:
http://www.advancedaquarist.com/2003/10/chemistry So your report sounds like a normal tank to me.
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Jonathan Bertoni |
02/28/2015, 09:16 PM | #3 |
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Thanks Jonathan. Interesting article. I just looked at the youtube video for the kit and will measure again tomorrow. I was not waiting a whole minute after adding the colored reagent before I added the EDTA to chelate the Mg. I will try again tomorrow and see if I still get 1400.
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02/28/2015, 10:46 PM | #4 |
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Okay, let us know what you get!
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Jonathan Bertoni |
03/01/2015, 06:26 PM | #5 |
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1360. so a difference of 20 uL on the EDTA. Not sure if that mattered or not but at least I know I am doing it per instructions exactly.
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03/01/2015, 06:40 PM | #6 |
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If your tank was losing 1ppm per week, (a tank full of S.P,.S corals could lose 1ppm per day), and you did a 5% weekly water change, then if the new water was 20ppm higher, t you would ne replacing the 1ppm, and never see a drop in mg. Test kits often only show drops of 20ppm, so it could de 20 weeks before you see a drop with the test kit, if you are doing no water changes. Your tank could be losing more or less that 1ppm, it just depends on the type/amount/size of coral, and lighting/growth rates.
It may be that the corals were under low lighting at the LFS to save money. If you see white edges form on the rim or tips of corals, this is one way to tell if they are growing!!. |
03/01/2015, 11:00 PM | #7 |
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Okay, 1360 ppm and 1400 ppm are within reasonable error limits, IMO. I agree that the tank's consumption rate probably is just very low.
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Jonathan Bertoni |
03/02/2015, 06:39 PM | #8 |
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Nicholasb,
Will ALL SPS display the white tips? I have some that do and some that do not. Scubajoe |
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hanna, magnesium, sps |
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