Ushio 20k+ 70W MH making colours pop?

[Chris2500DK]

I'm working on a new Nano project and I have this 70W MH lamp ( http://fastlight.co.uk/acatalog/Nano_Aquarium_.html ) with an old 10K bulb, and I found the Ushio 20K+ 70W bulb at a reasonable price locally.

What I'm wondering is if it would make the colors pop on it's own or if I'd have to add supplemental actinics?

[PaulErik]

The 70/75-watt Ushio 20,000K+ appears white/blue. I've found it to make fluorescent pigments in corals pop pretty well. Additional actinic lamps can be used to provide a bluer appearance and increase color pop but it isn't required. Note the 20,000K+ lamp will provide less light output than a 10,000K lamp. The 20,000K+ lamp may not provide enough light for some applications.

[redfishsc]

Howdy Paul. I used to live in your town, there off Bacons Bridge rd.


Anyhow, there was a study by Dana Riddle that showed that, on at least one SPS specie, 20K lighting actually promoted better growth (by a fairly strong margin) compared to 10K and 14K MH bulbs. Perhaps they put out a dimmer looking light, and show less PAR on the meters, but I believe that they are about as capable of good growth (and more capable for better colors) than 10K and 14K.... generally speaking.

http://www.advancedaquarist.com/2008/12/aafeature1

[DarG]

Originally Posted by redfishsc

Howdy Paul. I used to live in your town, there off Bacons Bridge rd.


Anyhow, there was a study by Dana Riddle that showed that, on at least one SPS specie, 20K lighting actually promoted better growth (by a fairly strong margin) compared to 10K and 14K MH bulbs. Perhaps they put out a dimmer looking light, and show less PAR on the meters, but I believe that they are about as capable of good growth (and more capable for better colors) than 10K and 14K.... generally speaking.

http://www.advancedaquarist.com/2008/12/aafeature1

Be very careful interpreting that study/article. It was not intended to make a sweeping generalization. It was focusing on light in the red spectrum inhibiting growth, and that there is less red spectrum in that 20K lamp and was meant to suggest that it may be feasible to do further, much broader research on the impact of the red "light" on more coral species . It was very limited in scope focusing on one specimen of one species of coral. The author makes this point very strongly. It was definitely interesting but also very limited as stated in the article and not intended to be generalized to all corals.
The fact that many reefers that have tried many different lamps still achieve greater growth rates in their displays using higher par, lower K lamps is pretty strong evidence that the results in the article may be indeed be limited to which species of corals it may apply to. The articles conclusions were suggestions for further study, not a call for reefers to use higher K lamps with little or no red spectrum in order to achieve higher growth rates.

That said, I love the Ushio 20K lamp as a stand-alone and I think it will work fine for your nano project. But if growth is limited, dont hesitate to try a lamp with higher par.