pics ?
some info
Baird et al. (2000) state that the DsRed fluorescence emission (from Discosoma) is insensitive to pH over a range of 4.5 - 12, and has a high quantum yield (0.7) at or near a pH of ~8.8. However, pH shifts within the coral tissue could conceivably cause a change in perceived coloration since absorption (excitation) maxima are caused by pH modulations - the wavelength absorption maxima falls from 558nm to 526nm as pH becomes lower.
'Metals ?
Any seasoned hobbyist knows that copper is toxic to marine invertebrates and avoids its medicinal use for fishes in a reef aquarium. However, even trace amounts of copper (Cu2+ & Cu+ ions in the parts per billion range) can bind with the wild-type DsRed protein as well as some of the engineered mutants and 'quench' (inhibit or stop) fluorescence (Rahimi et al. 2008). Fortunately, the effect is reversible as an addition of a chelator can reverse the effect and restore fluorescence. This quenching effect becomes more pronounced with increasing pH.
Other researchers also found evidence of metal-induced fluorescence quenching by cobalt and nickel (though not to the extent of copper - Eli and Chakrabartty, 2006). Zinc has been noted to reduce fluorescence in some of the genetically-engineered green fluorescent proteins (but we don't know which GFPs) but not in DsRed. See Figure 1 (note that this information is applicable to only the DsRed pigment and not any of its mutants).
more metals ?
Interestingly, some heavy metals have been found to marginally increase fluorescence of the protein found in Discosoma. Those with the most effect were (in descending order): Manganese, iron and chromium (Eli and Chakrabartty, 2006). See Figure 1.
Warning: These researchers were working with minute concentrations (mM) of metal concentrations. Resist the urge to dump a bucket of chemicals into your aquarium!
agh ... more metals ?
Eli and Chakrabartty, 2006 studied a number of metals and their effects on DsRed fluorescence. Those metal ions demonstrating no effects of were sodium (Na+), potassium (K+), calcium (Ca2+), and magnesium (Mg2+). The latter is of particular interest, since there are internet reports from hobbyists I respect claiming that low magnesium levels can cause loss of color in some Montipora specimens. See Figure 1.
from :
http://www.advancedaquarist.com/2009/4/aafeature1
KZ's B-balance helps with Reds ... can u guess whats in it ?
Conclusion :
In general, the fluorescence of DsRed pigments is not difficult to maintain in captivity. We have established that light (and blue light in particular) is important in the process of color promotion, although to varying degrees. Green light can promote coloration and in some cases, red light alone can make a coral weakly express pigmentation.
In some cases, temperature is critical (such as seen in the rose or bubble-tip anemone- E. quadricolor), where temperatures above 27C (~81F) inhibit coloration. On the other hand, the Keima pigment found in a Montipora species is stable at 37 C (98.6 F).
We have also learned metals can help promote or inhibit coloration. Metal binding to the protein definitely affects coral coloration, but it is unclear if those metals promoting fluorescence are required cofactors or simply a product of the binding.
HTH
I thought it was reds and pinks? I have yet to see a single shred of anything other than very poor anecdotal evidence to suggest any of the elements claimed to help with certain colors actually do.
