20,000K or 10,000K, which is better??

[dc8053]

I have a 75 allonf reef tank. I have A red brain coral, Antheilia, Derasa clam, Maxima Clam, Fire Coral, XLRG Green leather, Yellow Toad Stool, Chilli Coral, Curly Leather coral, Pavona, LRG pruple neo acropoa, and a large torch coral. I have 10,000K halides right now, 175 Watts each. Just wondering if 20,000 Halides are beter in respect to Colors of the corals. But I heard that 20,000K halides can burn corals. What should I do??

 

[q]

The par values are lower on the higher K bulbs. With clams I would leave the 10K on and if you want more blue do it with VHO or PC.

 

[adrian]

Like said above the 20K will be less intense as the 10K, some 20K bulbs put off a lot of UV, thats whay you heard they burn corals, you may need to use a filter in between the tank and the lights. I would sitck with the 10K, I like the tank to appear more white than blue, but if your looking for more blue you cant go wrong with 20K.

 

[ironreef]

there hasn't been a study that measures uv from halides that I know of. sanjay hasn't tested for it and theres alot off ppl who are looking for info on this. If so I would like a link that measures uv and bulbs. 20k ime doesn't burn corals anymore thna 6.5 10k. what burns corals is improper light acclimation= increasing lighting to fast or replacing really old bulbs with new and keeping the same lighting time.

 

[adrian]

Ironreef, im not saying all 20K bulbs will burn corals, Im simply saying that some bulbs emit more UV than others, some HQI bulbs for example that lack the UV filtering glass that other MH bulbs are encased in require a UV filter. If you do a search, there were several incidents of people getting UV burns from a certain brand bulb a while back, although I cant remember which bulb it was and I would hate to post the wrong one. Yes corals can be burnt if acclimated wrong, but they can also be burnt by too much UV, especially deep water corals.
Heres a link for you:
http://www.seaplace.org/riddle.html
"Certain types of metal halides, e.g. halogen quartz iodine lights, may need to be protected by a U.V. filtering glass. If you do not place such a barrier between the light and the tank corals may be burned by the ultraviolet radiation"
"You may have read in certain articles that metal halide lighting "burns" corals. This can only happen if you are using a bulb that needs a U.V. shield, and omit to install it."
And heres another:
http://www.netpets.com/fish/referenc...elbook12b.html
Let me rephrase my comment, certain metal halide bulbs, depedning on type, mogul ended, or dual ended, also depending on wattage, will require a UV filter to prevent burns to corals and your skin.

 

[ironreef]

hqi need a uv cuz they don't have the outer shield like mogul bulbs. But its been said uv is what makes sps color up. depends on what you keep.