Why would you Randy not dose strontium? Is it not needed in your opinion with decent water changing? Or do you mean you would stick to the off the shelf products?
I do not think either strontium or iodine supplements have a demonstrated utility. I have dosed them in the past, especially iodine which I dosed for years. I noticed no change on stopping, and there is no literature indication of utility for the organisms that we typically keep.
This article has more:
The “How To†Guide to Reef Aquarium Chemistry for Beginners, Part 2: What Chemicals Must be Supplemented
http://reefkeeping.com/issues/2007-04/rhf/index.php
from it:
Supplementing Iodine
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Many aquarists dose iodine, and claim that certain organisms need it to thrive. Often mentioned are shrimp, Xenia species of soft corals, mushroom corals, and more. However, no evidence for an iodine requirement by these organisms appears anywhere in the scientific literature. They also thrive quite well in many coral reef aquaria where iodine is not dosed. Of Reef Central’s Tanks of the Month for the past couple of years, the majority do not supplement with any form of iodine (or at least do not mention doing so), although some certainly do dose it.
I do not presently dose iodine to my aquarium, and I do not recommend that others do so, either. Iodine dosing is much more complicated than dosing other ions due to its substantial number of different naturally existing forms, the number of different forms that aquarists actually dose, the fact that all of these forms can interconvert in reef aquaria, and the fact that the available test kits detect only a subset of the total forms present. This complexity, coupled with the fact that no commonly kept reef aquarium species are known to require significant iodine, suggests that dosing is unnecessary and problematic. On the other hand, it is nevertheless possible that some organisms that we keep do actually benefit from iodine, and that in some aquaria there is not enough in the foods that we add so that supplements may possibly be beneficial in those aquaria.
I dosed iodine for several years when I first set up my aquarium. I dosed substantial amounts of iodide to try to maintain 0.02 to 0.04 ppm of iodide (which is a natural level). Iodide is rapidly depleted as algae and perhaps other organisms take it up and convert it into organic forms. After a few years of dosing iodide, I became frustrated with the complexities of testing for it, so at that point I stopped dosing any supplemental iodine. That was about seven years ago. I detected no changes in any organisms, and never dosed any again. If you are dosing iodine now, I suggest stopping for a month or two, and seeing if you can objectively detect any difference in any organism.
For these reasons, I especially advise aquarists NOT to try to maintain a specific iodine concentration using supplementation and test kits. For those who do supplement iodine, I suggest iodide as a more suitable form than certain other additives, such as Lugol’s iodine, which is unnatural and potentially more toxic. Iodide is also more readily used than iodate by some organisms, and iodide is detected by both currently available iodine test kits (Seachem and Salifert).
Further information on iodine can be found in these articles:
Iodine in Marine Aquaria: Part I
http://www.advancedaquarist.com/issues/mar2003/chem.htm
Iodine in Reef Tanks 2: Effects on Macroalgal Growth
http://www.advancedaquarist.com/issues/april2003/chem.htm
Supplementing Strontium
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Strontium may or may not be useful in coral reef aquaria, and it may or may not become depleted. Like magnesium, strontium becomes incorporated into calcium carbonate in place of a portion of the calcium ions. That incorporation happens to approximately the same extent whether a coral skeleton is being formed, or an abiotic (nonbiological) precipitate on a pump’s impeller. It is just a fact of life that strontium looks a lot like calcium, so it gets into places where calcium would otherwise be. Some aquarists have concluded that strontium may help corals to deposit their skeletons despite the absence of any evidence of this in the scientific literature, and of any direct experimental evidence (for or against) by hobbyists.
Some hobbyists do report positive effects of dosing strontium. Scientific evidence indicates that some organisms need strontium, albeit not the organisms that most reefkeepers maintain. Certain gastropods, cephalopods and radiolaria, for example, require strontium. There is, however, no clear evidence of any benefit of supplemental strontium in coral reef aquaria.
A few years back, when I tested my aquarium’s water for strontium (using a sophisticated lab machine), I found that in my reef aquarium, with no recent strontium additions, strontium was already elevated (15 ppm) above natural levels (8 ppm). By testing the Instant Ocean salt mix that I was using, I found that it, too, was elevated (15 ppm). I saw no evidence of depletion, at least not when performing my routine of changing 1% of the tank's water daily. I would not like to see the strontium level get any higher, because strontium is known to be toxic to some marine organisms at levels not too far above that. Consequently, adding a supplement without knowing the aquarium's current strontium level is not advisable.
Overall, water changes with a salt mix containing a suitable level of strontium may be the best way to keep strontium at appropriate levels, assuming it has any benefit at all. That requires no testing or worrying about dosages. For those who want to dose strontium, or who have very high calcification rates, which may deplete strontium faster than it can be replaced by water changes, I recommend testing to ensure that it does not get too high. My recommendation is to maintain strontium levels in reef aquaria in the range of 5-15 ppm. That level roughly spans the level in natural seawater of 8 ppm. I do not recommend that aquarists supplement strontium unless they have measured strontium and found it to be depleted below 5 ppm.
These articles have more detailed information on strontium:
Strontium and the Reef Aquarium
http://www.advancedaquarist.com/issues/nov2003/chem.htm
Magnesium and Strontium in Limewater
http://www.advancedaquarist.com/issues/dec2003/chem.htm
Whats your opinion (or/and others) on the baking of chemicals to make them weigh more accuratly? Would it work for calcium chloride and magnesium sulphate? Im not sure how well those chemicals hold onto their water.
That probably depends on the chemical, but it might be useful. For calcium chloride, I think the 77-80% in Dowflake is likely as accurate as a home dried version.
