Led back to Halide, T5, or combo.

[EW_Fish]

I rather have mh t5 combo but i'm on a tight budget and cant afford the cost of it so i'm with leds. ( had a hybrid combo for the longest time 120w with a ati blue plus & fiji purple)

 

[KologneKoral]

Todd,

very happy you don't feel offended, as this is not my purpose. Like you, exchange is what I love about these forums and would be excited to find a study that actually supports major use of red light by corals.

Mentioning the pocilliporids, which produce the non-fluorescent red (ish) pigments, pocilliporins. They are highly reflective, which I see as support that they are attempting to shield themselves from this part of the spectrum. I have a reflection graph of S. pistillata where the pink forms clearly absorb in the 560nm-600nm range and start reflecting strongly over this range, although another absorbtion peak comes at 680nm, which is only a lab result (the corals do not get this on the reef unless exposed to the air). As pistillatas are found from just below the surface to more than 30m, the species clearly has a wide range of adaption. does it require red light? Apparently not. Are the red reflective pigments involved in protection, probably, as the deeper forms tend to purple, the shallower tend to red-pink. We definitely need more study with this to truly understand. At this point we see a clear tendency.

Something that others have mentioned and I have to agree,the idea that a pigment we see reflects UV doesn't hold water, so to speak. We do not see most of the UV spectrum, which means a UV reflective pigment would appear clear or black to our eyes (we do know that they are clear). We would not see it. Again we have relied on human vision to define. Doesn't work. We are blind in much of the spectrum.

Yes, red pigments predominate at depth, as they appear black. No reflection of red possible due to depth, other colours can not be reflected by the red pigment, so we have black, no colour. Clearly they are not triggered by an encounter with this part of the spectrum, rather an adaptation that is inherited. Quite ingenious! Of course, when put in our tanks, they are brilliant in colour, like the Paracentropyge boylesi.

I would agree with you, most corals we keep are from relatively shallow water and many maricultured corals are grown at 5-10m. Still, less than 10% of the red spectrum is left at 5 meters. With such a small amount of usefull light it makes sense that the corals do not depend on it. It would be life threatening to do so. Make use of it as available, amny may. Could be genetic or epigenetic in nature. The last would make sense, in that we do see colour changes in corals under different light spectrum. Sounds like an epigenetic adaption mechanism.

We are moving off topic for this thread. We can certainly continue with PMs.

cheers,

Jamie

Hey Jamie, you are correct in studies showing Coral not to contain Chlorophyll b, and partially correct that Corals cannot use light wavelengths that they do not receive though there are some recent studies showing how some corals are capable of manipulating what is there to more of their liking by altering the wavelengths present (I'll check for a copy and post it) As to the Red spectrum, I'm taking an educated guess that around 70% of this hobbies Corals are collected in the top 30'/10m and 70% of these are in 15' or less where Red radiation is significant and there are studies by some of our fellow German scientists that found common shallow water Pocillopora species to have high amounts of both Chlorophyll a & c both capable and respondent to wavelengths exceeding 600nm. With my own undocumented study (of chance) I ran my refugium with just a Blue/Red LED grow-light fixture for over a year and not only had great macro algae growth used it as a stand in frag grow out station for my Birdsnests (Seriatopora hystrix & caliendrum) Stylophora, Euphyllia sp., Hydnophora and Montipora sp. all grew/encrusted a stayed colored (if seen under whiter light) as well as various zoanthids and a autothropic blue sponge. I know that the shallower the species or location of Coral the less symbiotic alga are present by lack of need and more UV absorbing pigments are to be found, often giving the Corals some quite vibrant colors. So if this a reaction to Red radiation would we not want more ? I'm not offended by any of your comments and nor is there any offense directed towards you. I love communicating with other intellectual Reefkeepers, and the diversity of the Reef makes for some fantastic subject matter.

Cheers, Todd

A fascinating side note about Red Pigments is that the deeper the marine life exists the higher percentage of Red pigments can be found. More invisible than silver or even translucence at depth.