questions about kelvin and ''blue look''

[flashyleopard]

I would like to thank everyone in advance for thier contributions to my up and coming reef.I am not completely new to the reef hobby,but have limited experience,so I invite the opinions of those more seasoned.

In my first reef tank,I managed to create unique aquarium wiht lots of ornamental algaes and was rather pleased.I like a crisp,daylight look to my aquariums and this scene depicted,to me,
a shallow lagoon.10,000k metal halides tend to be bluer than I enjoy,but I understand that the blue light is what makes it the deepest and thus,lights those inverts growing deeper in tank.I suppose I am asking what is acceptable to comprimise on as far as allowing the acroporas and other demanding types to prosper,but get a less blue cast to my tank.I think 6,500k is too yellow,so I am looking for maybe a 8,000k or 7,500k option.

Also,I have wondered why no one has tried supplementing the aquarium lighting with high intensity MV bulbs,used for reptiles to produce UVB radiation?My thoughts are that this form of lighting might be instrumental in keeping shallow water corals and invertebrates colorful,since many form those bright colors to defend against the intense UVB and UVC radiation they get in the wild.What harm could be done by attempting such a thing?I want to stated that the UVB bulbs would be used with standard metal halides and act as a supplement to conventional lighting,if I attempt this.Thanks everyone.

[DarG]

Check out the MH FAQ up top. There is a link to Sanjays site and he has tons of MH data. You can see that some of the 10000K lamps actually have color temps. that are 7000K, 8000K etc.
So, choosing one of those would be right in lione with what you are looking for. Check it out, lots of information in addition to just color temps.

[aninjaatemyshoe]

Actually, in general the lower Kelvin lamps have higher PAR values, which means they provide more beneficial light for corals. Highly demanding Acropora species and other light lovers will benefit from the higher PAR values in a low Kelvin MH lamp. From what I've seen, the Iwasaki 6500K bulb seems to have the best PAR for wattage. However, if this is too yellow you could go with a 10000K bulb that is more yellow than other 10000K's in appearance (the XM 10000K is a good choice).

As far as mercury vapor lamps go, I think some people have used and still use them. The colors that they come in are not prefered by the typical reefer, so that is most likely why they are hardly used.

[flashyleopard]

Thank you both for the advice.I had noticed that different 10,000K bulbs produced different color effects and wondered what that meant in regards to the quality of the light coming from the bulb.I am still in the research phase of my soon to be reef and have yet to jump intot he whole lighting pot of soup...lol

My last reef was a 46gallon bow front,lit by two 175watt metal halides,with 10,000K bulbs.I had some horn corals,pocillipora,acros,a carpet anemone,and lots of algae.I had halimeda,calurpa,red bubble algae(unidentified),a red fern-like thing I forgot the name of,other red sea weeds,and some red hydroids.
I like to include more fish than most in my set-up and tend to choose fish with a grazing habit and that need less feeding and produce less waste.I also added numerous hang on the back type filters for additional help in keeping the water quality in top shape.I started the aquarium with 40lbs of live sand and lots of uncured FIJI rock.I don't recall how long it cycled for,but before I added the corals and anemone,I used...gasp,just incandescent clamp lamp bulbs from Lowes.They were the 120watt grow lights by Sylvania....best macro algae growth ever...the algaes grew far slower under the metal halides and these flimsy red hydroids started coating the halimeda.The demise of this set-up was me moving and a few other issues that I am prepared for this go round.
I plan to use plastic egg crate and pvc pipes,like that use in flurescent lighting fixtures to raise my live rock off of the sand bed and blow a power head underneath the rock structure.This will prevent the detritis that tends to build when one has lots of algaes growing and dieing or lots of grazing fish from accumulating under the rocks and making a mess.I also am using a different filtration approach to this larger tank.I shall keep everyone posted and come her with my questions.Thanks again