20K vs 14K Metal Halide Bulb?? Advice Needed

[gooberz]

Hello All,

I recently put my 45 cube together and has a 250 watt MH fixture which is currently running a 10K Ushio. I would like to not add any more bulbs so i want the MH to come close to giving me a nice color in tank. I plan on keeping 90% SPS. I have the 14K Phoenix bulb as my Primary but some people tell me to go with the 20K Radium.

I am hesitant on the Radium because I want growth for my SPS and not sure how slower they grow with a 20K? :idea:

Thank you in advance!
Henry

 

[Phishguy]

Radiums are pretty unique bulbs. On the right ballast ( all the difference in the world ), you should get the same growth. Otherwise, supplementing the Phoenix with some royal blue LEDs makes for amazing color and very low operating cost. The other benefit of supplementing is the ability to light the tank before and after the main halide. Hope this helps

 

[frankpayne32]

Kelvin rating is more or less an arbitrary measurement on how the human eye perceives color, not necessarily a rating of what wavelengths of light a bulb produces. To make matters worse and more confusing bulb manufactures seem to be even more arbitrary in labeling the kelvin rating of their bulbs. Meaning one 14k bulb does have the same color as another brands 14k bulb. Your best bet is to mostly ignore the kelvin rating and go with bulbs that others have had the kind of results and color you are looking for. I run phoenix 14k bulbs myself and I love them. They last forever (at least 18 months realistically) and produce a crisp white light with just a hint of blue and good amount of PAR. Radiums are also great bulbs. They are bluer in appearance the Phoenix 14k but don't let that fool you. They put out a ton of PAR and many people have grown SPS corals like crazy with radiums. The whole 10k is better for coral growth than 20k is rubbish. It's actually the bulb of choice of many SPS keepers.

 

[gooberz]

Thank you for your replies, but now im really confused.. LOL My mind was set on the 14k Phoenix but the Radiums sound good as well and dont want to add more fixtures to get the actinics... HMMM....

Henry

 

[JMartin104]

It's my understanding that growth will be different for 14K vs. 20K. That being said, there are some very nice write-ups out there if you search. I ended up with Phoenix 14K MH bulbs and I'm happy with them. But then it's only my second replacement so I have nothing to compare it to.

 

[frankpayne32]

Thank you for your replies, but now im really confused.. LOL My mind was set on the 14k Phoenix but the Radiums sound good as well and dont want to add more fixtures to get the actinics... HMMM....

Henry

I hear ya, bulb choice can be very confusing. If it helps they both will grow corals great and Phoenix is a hell of a lot cheaper.

 

[Phishguy]

Radiums are the choice if you want no otter lighting at all. The important thing about radiums is having the right ballasts. There are tons of write ups about ballasts for radiums. Look up Sanjay joshi. He wrote articles for advanced aquarist and is well regarded as the guru of lighting. There is even a database of bulbs and ballasts combinations and par numbers. Very thorough. With the proper magnetic ballast, radiums will output more par than Phoenix and most other bulbs.

 

[gooberz]

I am running an Electronic ballast by hello lights.. Not sure if that would work??

 

[Phishguy]

With an electronic ballast, I'd stick with the Phoenix. That's what I use. You won't have the "pop" of radiums without anything for actinic supplement bit they are great bulbs and reasonably priced. I believe sos lighting is the least expensive. If I remember correctly, about $52 a bulb shipped.. Good luck and post some pics!

 

[alton]

I switched to 250w Radium lamps with Coral Vue Electronic ballast and the growth has been amazing on my SPS.

 

[gooberz]

Thanks Alton,

That helps me a lot as i was worried about growth.

Henry