400 watts... 10k or 15k XM?

[TheCampbells]

Just wanted to hear some suggestions and preferences. I am ordering the new bulbs tomorrow night. Thanks

[::pete::]

10K for growth.

[GaryP]

Mogul or DE?

I like the 10K Mogul bulbs I am using because it gives you a really nice peak at 420 nm. They haven't posted the specs on the 15K bulbs on their website yet. Its still new. Remember that you give up PAR the higher the K value you go to. The lower the PAR, the lower the growth rate. You give up growth for color. You just have to figure out what you want more.

[NaCl_H2O]

Personally, I don't like the blue of bulbs above 10K, and you will give up lots of growth.

[ReefOne]

yup, 10k w/ VHO Super R's is what I would recommend.

[witecap4u]

Im running 2x400 xm 10K's on my 100g with 220vho actinic's. Pretty decend color, nice crisp white. The actinics dont really change much, kinda wish I had twice the actinics...

If you'd like to check mine out, your more than welcome to.

cs

[scuba_steveo]

my vote....15K
yes you give up some growth but you get color!
and it is not too blue like the 20k

[VeeDub]

As someone who has used both XM 10K and 15K, I prefer the 15K.
The 15K is quite a bit more blue. I have a purple acro that was never really purple anywhere but the tips for around a year. Now, the acro is coloring up nicely after only a couple weeks with the 15K. I was willing to sacrifice growth for better coloration. IMO, the 400 10K just washed out the coloration of the corals. I was never able to supplement enough ActinicR to get a nice balance- always super bright white. I do wish for a bit more white but the coral colors look better than ever.

[TheCampbells]

I am currently using the 175s... 12k sunbursts with 440 vho. I planned on just using 10k with 440 actinic when I upgraded to 400s. My wife likes the blue, I like the white. I am still undecided......

[Tim Marvin]

10K with T-5 actinics

[Dozer]

I am currently using the 175s... 12k sunbursts with 440 vho. I planned on just using 10k with 440 actinic when I upgraded to 400s. My wife likes the blue, I like the white. I am still undecided......

Based on what you just said you both like it sounds like 15K makes sense. 15K or even 20K are definitely more blue and white. 10K are definitely yellow. Sounds to me like you're saying color/aesthetics is more important in your case than faster growth.

If it were me, I would try the more blue- 15K's- and see if you like them without any actinic support. If you do, you're done and that's easy. If you don't, you could always add the actinic flourescents later and just buy 10K bulbs when it comes time to replace the 15K's.

I personally have 2X250W DE's with 20K- which most people here would probably think was too blue. However, it was recommended to me by someone I trust (Greg- 360Reef) and my wife and I decided that how it looked was more important to us than faster growth. The 20K's look bright and crisp with definite cooler blue/white coloring. We like them, especially at night- and we're happy with the growth rates we're getting (softies are exploding, SPS are coming along decent). Point is most people here wouldn't like the 20K's but they work for us, so you never know.

Btw, I have seen Chris (VeeDub) 15K's that he's speaking of and they look great for display, imo.

[TheCampbells]

ok, I went with the 15k. They will be here on Monday, probably won't get put in until Tuesday, May some pics by next week.

[bigdscobra]

What is the par on the 10k, 15k, 20k???

[TheCampbells]

the new bulbs are in :D So far I love the color. I know it will change as the bulbs burn in. Only one problem, My vhos aren't coming on now. I guess that gives me a project for tomorrow though. Hopefully I will post some pics soon. Thanks for all the advice and links.

[bprewit]

<Should have gone 20kk, the data just came out and the PAR on the 15kk is actually lower than theh 20kk.>
I have been looking for the par of the new 15K and have not found any info on it yet. Where did you find the data?

[hammondegge]

yeh, me too. cant find par anywhere.

[VeeDub]

Forget the par on the XM15K- Par isn't everything. Might be relevant on the 250's or 175's but on the 400's, plenty of light gets into the tank.
Might also be relevant if you intend on fragging your corals constantly.
My corals look so much happier now with the lower par. I am actually getting some color back on some corals that the 10K XM's cooked.
I was initially concerned about par specs on the 15K but I am happy and the corals are happy. Now my thoughts about the XM15K par specs is-who cares? 20K is just too blue for the increase in par. 10K was too much par for my particular system.
Don't buy bulbs just for the specs. I went with 10XM's and my corals suffered for it- I just had to have the highest par specs that I could get my hands on.
The high par slowly bleached and washed out the corals but they are coming back nicely now after 3-4 weeks of the 15k.

Specs are everything to some people. These are the same people who would buy a 5"x5"x5" amplifier because specs say it's 1000 watts. I will take the 5'x5'x5' amplifier that pushes 20 watts every time.

I think you made a good decision going 15K.
Besides, all that matters is that the corals are happy and you like it.