Can 20K XMs match Radiums for color?

[Covey]

I am now ready to drop a fortune in the next week in lighting. My tank is a 29" deep 150G. It is going to be almost entirely SPS. The defacto color king seem to be the 20K radiums but I feel the have some serious drawback mainly the price and the short usable life(6 months). My tank is 6' long and I would need a 3 bulb set up to light it properly. So the bulb replacement cost would be around $540 yearly for the radium. Ouch.

Anyway I was wondering if any of you had switched back and forth and had any input?

I was wondering if the 20K XM can keep the kind of color in the SPS expected out of the radium and what the usable life span of the XM 20K were?

 

[Shawnts106]

Not sure here... But I have heard through the "grape vine" that the Radiums loose their spectrum after only 4 to 6 months where XM's are suppose to last for 12... not sure that I believe that...

I would like to hear from some lighting experts before I go and say anything more...

 

[Ti]

I used XM 20K for 1yr

 

[Stoney Mahony]

I have had 2 20k 400w XM over my tank for about two months and through pictures and to the eye I can not see a change in spectrum yet.

 

[easttn]

XMs are good up to a year, Radiums 7 months. I switched back and forth depending on the deal at the time I needed them. SPS colors remained the same. XMs are more blue to my eye than radiums, otherwise I don't think the coral reacted differently. $90 is pretty steep for those bulbs though.

 

[AlgaeMan]

IMO 400w XM 20k's on m59 ballasts will color corals much better than Radiums on any ballast. I've tested numerous bulbs and ballasts and this seems to be the best combo I have seen. For the Radium to even compete with the XM on the M59 ballast it needs to run on an HQI ballast. Using an HQI ballast will reduce the life of the bulb and use alot more power. IMO I think the XM's need to be replace every 8-10 months for peak performance. According to Sanjay's results the XM has almost twice the blue spectrum as the radium on an hqi ballast. In the long run you will save alot of money running the XM's.

 

[Covey]

Does anyone want to show off there 20K XM pics?

 

[Ceak]

I've seen Reeflux 12Ks on the same tank with XM20Ks and they looked identical on 250W electronics...

 

[BreadmanMike]

Covey,

I'm running 2 400W 20k XM's on m59's in the center of my tank. On the outside's I've got 250w Radiums running on HQI ballasts. I don't run any supplemental lighting at all. The colors are almost identical to the naked eye. The difference comes when you move corals back and forth to see how the colors change. Everything that has green in it really "pops" under the XM's. Almost like if it were under Actinic VHO's.

I was previously running all Radiums, but wanted to get better par under a 20k bulb. I'm very happy with the XM's and will most likely make the switch and run 4 of them.

 

[Covey]

It sound as though I am going that way. I am liking that the XM runs best on plain old m59s. Versus needing a pricier ballast.

 

[AlgaeMan]

Here is some great research.
The lighting bible

 

[Aquaduck]

Here's my tank running 2 400W 20K XM's on plain jane M59's. I think they look almost identical to Radiums except the XM's are a tad more blue. My camera doesn't like to take pictures of these bulbs very well. It's much brighter than this in person.

 

[BreadmanMike]

<a href=showthread.php?s=&postid=7457674#post7457674 target=_blank>Originally posted</a> by Aquaduck
Here's my tank running 2 400W 20K XM's on plain jane M59's. I think they look almost identical to Radiums except the XM's are a tad more blue. My camera doesn't like to take pictures of these bulbs very well. It's much brighter than this in person.

You just don't get that "pop" in the greens with the radiums... I love the XM's

Nice reef!

 

[elephen]

<a href=showthread.php?s=&postid=7446315#post7446315 target=_blank>Originally posted</a> by Shawnts106
Not sure here... But I have heard through the "grape vine" that the Radiums loose their spectrum after only 4 to 6 months where XM's are suppose to last for 12... not sure that I believe that...

Aparently your grapevine is tainted

I've run both and can say I like the color of the Radiums more, its a more intense light and IME the Radium is just a higher quality bulb.

Ive been running mine for 2 years now and replace them every 12 months on the dot and corals color and grow fine even at 12 months. Now if you run them on an HQI ballast some people change them every 8-9 months but I don't, I give them a full 12 and notice no ill effects.

 

[elephen]

<a href=showthread.php?s=&postid=7457717#post7457717 target=_blank>Originally posted</a> by Aquaticman74
You just don't get that "pop" in the greens with the radiums... I love the XM's

My greens pop just like that under Radiums. Out of curiousity have you ever seen Radiums in person or just in pictures on RC?

 

[MSHUR]

elephen,
i agree with u about radiums) very good bulb and hier quality
i run them on hqi and i love the color much better then anything else. i have try aq-14k ,also very good bulb ,but pricey and hard to get. but, i do change radiums every 8 month.

i am changing my t-5's set up and not sure what to get..)
do u think i should get one actinic and two 11k together with two radiums?


mike

 

[Ti]

<a href=showthread.php?s=&postid=7457674#post7457674 target=_blank>Originally posted</a> by Aquaduck
Here's my tank running 2 400W 20K XM's on plain jane M59's. I think they look almost identical to Radiums except the XM's are a tad more blue. My camera doesn't like to take pictures of these bulbs very well. It's much brighter than this in person.

Nice pic!

 

[BreadmanMike]

<a href=showthread.php?s=&postid=7457874#post7457874 target=_blank>Originally posted</a> by elephen
My greens pop just like that under Radiums. Out of curiousity have you ever seen Radiums in person or just in pictures on RC?

I see them everytime my tank lights come on... They do not give the color the XM's give which I also see everytime my lights come on....

2 400w 20k XM's m59 ballast + 2 250w 20k Radiums SLS HQI ballast.

 

[jnb]

 

[bskiba]

XM 20k is one of the better bulbs as far as color of coral and par. on a standard balast it has higher par than the hamilton 14k and the radiums. sanjay has done all the spectrum research on them and I can remember the xm being the best 20k bulb a year ago. the best combo would be 20k xm with 10k mixed in. corals would really color up well.