[ZBT3091]

Are vitamins and supplements ie.(Iodine, Iodide, Calcium...) really needed to add to a reef tank or is there going to be enough supplementation from natural light (440Watts for a 75 g tank) and mature sea water

[greenbean36191]

In most tanks with even moderate coral or coralline growth Ca and alkalinity will need to be supplimented. Water changes should take care of the rest. Animals don't get a whole lot in the way of vitamins or nutrients from the water anyway. They get it from their food.

[charlie]

IMO, not really. Alot of it depends on what types of coral you have, but if you keep up with your water changes, you should be able to keep most of your trace elements up to snuff.

[leebca]

Actually marine fishes absorb vitamins, nutrients, and organics through their mucous membrane and their skin. They also 'swallow' them during their osmoregulation process. Studies show that fish take on the vitamins added to water, the aloe-like products produced by macro algae, and soluble elements.

I recommend elemental additions to large marine systems and none for the small systems -- with regards to fish (not the inverts). In small systems, the normal, regular water changes should be good enough. (Again: only with regards to fishes). Live rock and reef systems will need (at least) the monitoring of Magnesium, Calcium, and Alkalinity with additions/changes when needed.