So about a year ago I switched over to BRS two part. Which includes a half gallon of magnesium chloride and a half gallon of magnesium sulfate to make your own magnesium mix with a 5:3 ratio of MgCl2 to MgSO4 (by volume). So I mixed it up and used it up over the course of 6-9 months. When it was time to make more I found that I had far more MgSO4 than MgCl2 left. So I decided to mix what was left with the reverse ratio rather than order more or waste some of it. So I had a solution that was mostly MgSo4.
Recently I setup a new aquarium. After about a month I checked my levels. Ca and Alk were normal but Mg was at a whopping 800-900 ppm! While I had been dosing CaCl2 and NaCO3 I had not been dosing that much so I wouldn't have thought it would drop that fast (5-7.5ml of each solution per day in a 30 gallon tank, by my math that should only produce a 4 ppm drop in Mg, not 400 ppm). Or perhaps the salt mix had low Mg from the beginning? I used red sea coral pro for those curious. Anyways this had to be corrected immediately. I grabbed my gallon of Mg mix and started dosing 500ml at a time then retesting. Ended up using about half a gallon to bring the Mg up to 1400 ppm.
This was several days ago and none of my corals or fish have shown any sort of reaction. However my brittle star has been barely moving since around the time that I did the Mg dosing. It could be (and likely is) a coincidence since I can't be sure that it started on exactly the same day but it got me thinking that perhaps I overdosing the So4 levels and that is what is causing him trouble. By my math my SO4 levels would have gone up 60% from the dosing. So I looked for some SO4 test kits in case I ever ran into this problem again and needed to confirm it. And to my astonishment, there are none.
Why would this be given that many of us dose it as part of our Mg dosing, it's been shown to be elevated in many ICP/triton results, and it's been shown to be toxic to most marine invertebrates at levels as low as triple NSW? Isn't the old adage supposed to be "don't dose what you can't test"?
I will do a 50% water change this weekend but for now the tank seems fine overall. I'm also surprised on the lack of both test kits and research done on chloride, sodium, and sulfate levels. I for one would like to know how important it really is to keep these major ions in the correct ration, what the acceptable range of levels is, and how it affects marine life outside of this range. But there seems to be no data on any of this. Sure you can correct them a bit with water changes but that's a lot of potentially unnecessary work if we just do more research on the subject not to mention that it can't bring them completely back down to the correct levels without you also lowering salinity (which also lowers levels for everything else we don't test for).
I would love to switch to kalk to minimize the possibility of sodium/chloride/sulfate building up but I cannot get the stuff to settle. It literally takes weeks to settle in RO/DI water (and days in tap water). And the particulates are too fine to filter out without letting them settle. I've tried three different brands (generic ebay, BRS, and Mrs. Wages). I have found that fresh kalk tends to settle reasonably well and sealing it in a truly airtight container extends that but even so within a month or two after buying it it's right back to this behavior. I believe it has to do with moisture in the air causing it to precipitate as CaCO3 while it's still in the container. But after storing it in a dry area, using a double sealed air tight food storage container, and adding a desiccant I don't know what else I can do at this point.... Also I have tried vinegar and that makes it even more cloudy! A lot more in fact. Even when it's brand new it still doesn't mix as fast or as clear as many of the videos I have seen on kalk mixing. Am I doing something wrong? The water is at room temperature neutral PH.
TL
R: Read the bolded sentences. Thanks in advance.
Recently I setup a new aquarium. After about a month I checked my levels. Ca and Alk were normal but Mg was at a whopping 800-900 ppm! While I had been dosing CaCl2 and NaCO3 I had not been dosing that much so I wouldn't have thought it would drop that fast (5-7.5ml of each solution per day in a 30 gallon tank, by my math that should only produce a 4 ppm drop in Mg, not 400 ppm). Or perhaps the salt mix had low Mg from the beginning? I used red sea coral pro for those curious. Anyways this had to be corrected immediately. I grabbed my gallon of Mg mix and started dosing 500ml at a time then retesting. Ended up using about half a gallon to bring the Mg up to 1400 ppm.
This was several days ago and none of my corals or fish have shown any sort of reaction. However my brittle star has been barely moving since around the time that I did the Mg dosing. It could be (and likely is) a coincidence since I can't be sure that it started on exactly the same day but it got me thinking that perhaps I overdosing the So4 levels and that is what is causing him trouble. By my math my SO4 levels would have gone up 60% from the dosing. So I looked for some SO4 test kits in case I ever ran into this problem again and needed to confirm it. And to my astonishment, there are none.
Why would this be given that many of us dose it as part of our Mg dosing, it's been shown to be elevated in many ICP/triton results, and it's been shown to be toxic to most marine invertebrates at levels as low as triple NSW? Isn't the old adage supposed to be "don't dose what you can't test"?
I will do a 50% water change this weekend but for now the tank seems fine overall. I'm also surprised on the lack of both test kits and research done on chloride, sodium, and sulfate levels. I for one would like to know how important it really is to keep these major ions in the correct ration, what the acceptable range of levels is, and how it affects marine life outside of this range. But there seems to be no data on any of this. Sure you can correct them a bit with water changes but that's a lot of potentially unnecessary work if we just do more research on the subject not to mention that it can't bring them completely back down to the correct levels without you also lowering salinity (which also lowers levels for everything else we don't test for).
I would love to switch to kalk to minimize the possibility of sodium/chloride/sulfate building up but I cannot get the stuff to settle. It literally takes weeks to settle in RO/DI water (and days in tap water). And the particulates are too fine to filter out without letting them settle. I've tried three different brands (generic ebay, BRS, and Mrs. Wages). I have found that fresh kalk tends to settle reasonably well and sealing it in a truly airtight container extends that but even so within a month or two after buying it it's right back to this behavior. I believe it has to do with moisture in the air causing it to precipitate as CaCO3 while it's still in the container. But after storing it in a dry area, using a double sealed air tight food storage container, and adding a desiccant I don't know what else I can do at this point.... Also I have tried vinegar and that makes it even more cloudy! A lot more in fact. Even when it's brand new it still doesn't mix as fast or as clear as many of the videos I have seen on kalk mixing. Am I doing something wrong? The water is at room temperature neutral PH.
TL
R: Read the bolded sentences. Thanks in advance.
.
. Also I hate water changes and only do them when absolutely necessary. My dream is that one day we will understand the chemistry of coral uptake and seawater well enough that water changes will become counterproductive. Many companies already claim to do this (e.g. triton) with promising results but none will release enough data to make their testing replicable. 
