XM DE 250 Watt 10K vs 15K vs 20K

[morbius18]

I'm buying a new bulb for my MH fixture and want a new bulb. I don't know what type that I should get. I like a blueish light, but I've read reviews that the 15K suffers from low PAR, and I know that the 20K is lower, so is the best bet the 10K with actinic? Hopefully someone with some experience can help me with this.

 

[BigAl07]

I've done "All of the above" and honestly "Low Par" is a relative term. It's just "Lower than 10k" but according to my SPS growth it's not LOW-PAR.

I started with 10k then bought 14k (loved them) then went 20k. I'm LOVING 20k. The look is a definite "Crisp Blue". It's really up to you. I'm not trying to do a "Frag Grow-out" system with my 90g so I'm not really trying to "Push" the corals for massive growth.

 

[faust]

i ve done the xm15k wasn't happy and color shifted on me after 6 months. i had much better luck with phoenix 14k's. my new fixture use giesseman with megachromes. i suggest them if your budget allows if not use the phoenix

 

[morbius18]

If I go with the 20K I also have 2 65 watt PC bulbs to get. Actinic with 20 K would probably be too much, so would 50/50 work or should I just go with something like 10Ks.

 

[morbius18]

Where online sells the phoenix bulbs, I was using drsfostersmith for the bulb selection as they have been my primary online source.

 

[mcarroll]

10,000K's for growth, 20,000K's for looks has been the rule of thumb I've seen most.

Nothing wrong with XM 20,000K's for sure (I use em), and I've heard that Phoenix 14's look more or less like 20,000K's as well.

Not sure about 20's with your actinic PC's tho...I suppose it's possible to overdose (you, not the corals) on blue. ;-) Maybe shift the PC's to a new frag or quarantine tank? Or just put 50/50's in them as you suggested in the first place.

-Matt

 

[reefer4200]

I use 12k's and i love them! They have a wonderful blue to them and they dont loose out like the 15 and 20k.

 

[ati70cutlass]

i have a xm hqi 250 watt i would sell. its a 10k. i used it for about a month. so its broke in. has a slight yellow tinge but with 2*96 watt 420 nm actinics it looks white. i was experimenting with 10-14-20 . as far as growth the 10k had huge response over all the others. ill let it go for 50.00 shipped. let me know if anyone wants it. procharged70cutlass@live.com

 

[Frankie]

Tough choice. I am a 20k person but it all really depends on the ballast also. Some ballasts drive bulbs harder making them more white then blue. Take Radium's for example. They only come in 20k btw, on a HQI ballast (what they were intended for) will have more of a crisp white with a hint of blue to them. On a Eballast like the Galaxy they have the same look but the par drops a bit. Not much though on that ballast. On an Impulse or magnetic ballast they are very blue, almost monochrome.
The reason I mention all that, it is a good basis to go by for all bulbs and ballast mixes. The 14k Pheonix is another great bulb but again will have different pars and colors depending on the ballast.