You can always stop dosing silicate if you don't like the results. It depletes rapidly.
I personally don't think iodine is useful for most reef tanks.
This has more:
https://www.reef2reef.com/threads/o...-reef-aquarium-by-randy-holmes-farley.173563/
from it:
Iodine
I do not presently dose iodine to my aquarium, and do not recommend that others necessarily do so without verifying for themselves that it is useful in their tank. Iodine dosing is 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 often detect only a subset of the total forms present. This complexity, coupled with the fact that no commonly kept reef aquarium species are known 9in the scientific literature) to require significant iodine, suggests that dosing is possibly unnecessary and problematic.
I dosed iodide for years, and then stopped and never saw any difference in any creatures I kept (including macroalgae, shrimp, etc., but I obviously have never kept every possible creature that others may keep). Many others have reproduced that finding. Still others, however, are convinced that iodine is useful in their aquaria.
Iodine in the ocean exists in a wide variety of forms, both organic and inorganic, and the iodine cycles between these various compounds are very complex and are still an area of active research. The nature of inorganic iodine in the oceans has been generally known for decades. The two predominate forms are iodate (IO3-) and iodide (I-). Together these two iodine species usually add up to about 0.06 ppm total iodine, but the reported values vary by a factor of about two. In surface seawater, iodate usually dominates, with typical values in the range of 0.04 to 0.06 ppm iodine. Likewise, iodide is usually present at lower concentrations, typically 0.01 to 0.02 ppm iodine.
Organic forms of iodine are any in which the iodine atom is covalently attached to a carbon atom, such as methyl iodide, CH3I. The concentrations of these organic forms (of which there are many different molecules) are only now becoming recognized by oceanographers. In some coastal areas, organic forms can comprise up to 40% of the total iodine, so many previous reports of negligible levels of organoiodine compounds may be incorrect.
The primary organisms in reef aquaria that "use" iodine, at least as far as are known in the scientific literature, are algae (both micro and macro). My experiments with Caulerpa racemosa and Chaetomorpha sp. suggest that iodide additions do not significantly increase the growth rate of these macroalgae, which are commonly used in reef aquaria. Other macroalgae species may respond differently, but none are known in the scientific literature to “need†iodine.
Finally, for those interested in dosing iodine, I suggest that iodide is the most appropriate form for dosing. Iodide is more readily used by some organisms than is iodate, and it is detected by test kits. While many people use it and are happy with the results, I am not a fan of Lugols iodine (a mixture of I2 and I-) because it is reactive and unnatural. With that as a backdrop, my recommendation is to experiment with iodine if you want, but be ready for there to be no benefit and to stop if that seems the case. For reasons relating to the complexity of iodine forms and testing, I usually advise aquarists to not try to maintain a specific iodine concentration using supplementation and test kits, but to dose something like a NSW equivalent once a week or so.
I would also avoid commercial timed release iodine products. I do not know what any of these products actually are, but most likely they are an organoiodine form of some sort. There is little data available on the effects of such compounds in aquaria, and I see no reason to experiment with them.
And these have a lot more if you want all of the science:
http://www.advancedaquarist.com/issues/aug2002/chem.htm
http://www.advancedaquarist.com/issues/april2003/chem.htm
