soft coral ??

[sandman3467]

The calcium that the coral can use can come from the dissolved calcium in the sea water surrounding them or it can come from their food. Calcium is a major component of both skeletal and muscular systems in all animals, and so animal plankton food is an excellent good source of this material. Small-polyped corals such as Acropora and Seriatopora probably can't get much of their calcium needs from this pathway, as they can't eat larger animals. However, some of the larger-polyped animals certainly can get the majority of their calcium from feeding. I once fed a small Fungia, which was about 3 cm in diameter, a number of small fish chunks daily. Over the course of two months, it more than doubled in diameter and thickness; during this period, I never once saw it defecate bones from the fishes it ate; they were turned into coral skeleton.

Feeding provides necessary protein and calcium to corals. Regardless of their ability to absorb these materials from the surrounding medium, feeding is probably the primary natural source of metabolic nitrogen and an important source of metabolic calcium.

 

[sandman3467]

Trace nutrients are those necessary for the organism's growth or well-being, but only necessary in very small amounts. They can include metal ions, inorganic mineral nutrients or organic materials. The actual trace nutrients necessary for coral metabolism are unknown. Simply put, no scientific research has been done on this topic. Aquarists have built up quite a mythology around additives to marine reef tanks, but in most cases there is no scientific rationale for adding most of these additives.

Amongst the known necessary additives are some small levels of metal ions, such as cobalt, copper, iron, and magnesium. These materials are necessary in all animals in very small amounts to facilitate enzyme functions. The concentrations of these are regulated very well by the animals, and the animals conserve these materials; almost none are lost in wastes. However, amounts only slightly over natural sea water concentrations of many of these metals may be lethal. Aquarists can add these, of course, but it is at the risk of killing their animals. In many cases the corals appear to sequester these materials directly from sea water, but they also get them from the foods they eat.

Other necessary additives are organic materials such as including vitamin B12. These materials are biogenic in origin, and in most cases they have to be gotten from food; bacteria for example are an excellent source of vitamin B12. Vitamins, by and large, are defined by their action on humans, and most have absolutely NO known effect, either positive or negative, on other animals, particularly animals such as corals whose metabolism is significantly unlike that of humans. Addition of vitamin C or other human vitamins probably makes the aquarist feel better, but probably has no real effect on their animals.

A third type of material is often added by aquarists. These are materials that have anecdotal benefits or good sales reps... Probably the most ubiquitous of these is strontium, which has no demonstrated positive effect in the metabolism of any animal except some larval opisthobranch snails, and then only for a brief period. Strontium has been demonstrated to reduce the transport of calcium ions across coral epithelial tissues, so concentrations above those found in natural sea water probably have an inhibitory effect on coral growth and well-being. Chemically strontium acts very much like calcium and substitutes for calcium in many biochemical pathways, but where calcium is specifically necessary, strontium would be an inhibitory poison. Whatever, the additive, however, these are generally added in solution, and the animals may absorb them across their body surfaces.

 

[Lynn]

Does a person still need to keep the calcium up, if you have soft corals only??