Questions About Metal Halides

[demasonisrule]

I'm running a 150 watt 14,000 k metal halide bulb above my reef, and it looks way to yellow for me. So I was wondering, can you swap a 14,000 with a 20,000 if its the same watt? I've read a boatload about how bad of an idea it is to swap the bulbs, but its all about the wattage, not the color temp. T5's or the like aren't an option, but an LED strip maybe? Any other ideas?

 

[Crazy fishes]

When running a reef we are trying to take a little piece of nature into our homes. The sun has a temperature of 6500 K hence it is visibly very yellow. However the sun radiates much more energy per unit area than we can realistically supply. Most of bulbs have been shifted up the kelvin scale to give us the familiar 10,000K, 14,000K and 20,000K lamps and the reason is because we can then supply the more energy rich frequencies to our corals at a more affordable cost. The reason changing from a 14,000 K to a 20,000K lamp is generally considered bad is that corals have evolved to handle the spread of frequencies presented by the sun. If you place them under a 20,000K lamp you are supplying mostly the blue end of the spectrum which incidently is the most energy rich. Corals have not evolved mechanisms to handle that much "blue light" and are generally "burnt" leading to bleaching of the corals. The science is that the algae in the corals tissue (AKA zooxanthellae) produce oxygen at a rate proportional to the light they receive and have no mechanisms to buffer the excessive volume of toxic oxygen species generated at very high light levels. So you see corals aren't really physically burnt they are chemically burnt which results in an act analogous to you having a mouthful of REALLY hot tea!!

Hope this explains

Kindest regards

Joe

 

[ColdwaterJosh]

Aslong as the wattage is the same for example a 70w Metal Halide, and you replace the bulb with a 70w 20,000k bulb, it will be fine. I have done this, and so has my brother and both our reefs are fine!

If your from the U.K. Iquatics have the best prices on Metal Halide bulbs, and are very cheap and great quality, plus free shipping!

http/www.iquaticsonline.co.uk/index.php?option=com_virtuemart&page=shop.browse&category_id=28&Itemid=53&TreeId=1&redirected=1&Itemid=53

 

[ben1987]

it would be ok imo

but you wont get anywhere near the PAR from a 20k compared to a 14k. id say its probably the quality of the bulb as 14k are usually pretty blue anyway

 

[demasonisrule]

Thanks for that Joe, I'll keep a close eye on my corals if I decide to get the 20,000.

Yeah, I'll be keeping mostly softies and low light LPS, so with the MH I'm not too worried about the power, but I really like the look of the really really blue tanks. Maybe it just looks yellow because of all the algae on the rocks

Once all the algae is clear, if it still looks too yellow, I may just get some cheap LEDs just to try that idea, although I'm not sure if it will be strong enough to make a difference.