10k vs 14k vs 20k
 

What is the difference between these different bulbs? Does anybody have an article they can link me to or something that I can read to learn about this. I am running a 20k XM single ended bulb right now. I'd love to see pictures of the different lights on the same tank. Thanks in advance.

Basic rule of thumb is the lower the Kelvin, the faster things grow (including algae) the higher the Kelvin the better the coral colors up.

higher the k, the bluer the bulb.

http://www.marinedepot.com/lighting_...mation-ap.html

Also lower the k more yellow the light higher the bluer

I'm curious in particular about the 14k hamiltons and phoenix. Also the 20k XM and radiums.

the 14k hams are white with hint of blue.
the phoenix are very blue
xm 20k very blue
radiums very blue, hint of purple

where could I find pictures with these comparisons on the same tank? Basically this is my first tank and I want to decide on what bulbs I like for my 120 gallon tank but don't want to have to purchase them all just to test them out...

did u see the link?
thats the only one i know of.

You can find them on your thread. :idea:

Here's another..
http://www.marinedepot.com/lighting_...tion_2-ap.html

i think one of the best combos is the radiums on a hqi ballast. this is the ballast that the radium are meant to run on. the ballast will over drive the bulb and make them white with hints of blue.

check out mpollotis totm write up

Here's the best link I know of to give you what you're looking for. It's getting a bit dated as it doesn't contain any newer bulbs but it seems to hit some of the favorites.

http://cnidarianreef.com/G180/lamps.php

Radiums are by far the most popular and the performance cannot be matched. However, like anything in life, you must be aware of the drawbacks. More specifically, Radiums should be changed every 6-8 months.

Primary Goal:
Growth - 6,500K - 10,000K
Color - 14,000K - 20,000K

Generally when I run a SPS reef, I use Iwasaki (6,500K) or XM 10K to grow out the corals for 1-2 years and then switch to Radiums to color up the corals.

perfect! That was just what I was looking for. I guess I will get the hamilton's 14k and give those a shot compared to the 20k XMs. Is there anything I should know when switching from 20k bulbs to 14k?

The hamilton bulb has a great color but beware it will crap out on u in no time . Make sure to keep the reciept to send them back to HT when they shift . No too much of a switch to worry about .

Sort of a crude but useful guide. For me 17K is the most pleasing to look at.

I totally agree or at least back when I was using MH.

This is the first time I've heard that. Can you elaborate a little bit more for me please? I've been using a Hamilton 14K bulb for almost 9 months now and haven't seemed to have any problems. It's a 175 watt SE being run on an older Hamilton magnetic ballast.

so what would I be needing to do in terms of acclimating them or switching from the 20k to the 14k?

when i used to run MH i ran 400w SE radiums on HQI ballast. the HQI overdrives the bulb a bit and makes it less blue. I really loved the color and growth was really good. i ran a 400w 10K xm SE on a HQI ballast and the color wasnt horrible but growth wasnt THAT much better to make me want to run 10k over 20k. point being is that there wasnt a super noticeable growth difference but there was a color difference. I also ran pheonix 14k SE 250w and it had good color but i wouldnt trade it for the radium.