Switching from XM 10K to 20K

[ClubReef]

Hi,

My XM 10K (250watt SE) bulbs are up for replacement and I'm considering the XM 20Ks. Since these bulbs have lower PAR value, will I see bleaching, browning or other effects? Should I be cautious and reduce my photo-period for the first little while?

This will be my first bulb swap so any advice for this tansition would be appreciated.

thanks

 

[beeker]

no you only see those signs when going from lower PAR to higher PAR, i would say do you normal photo period and leave your lights at the same height. I'm not sure of the PAR on the 10k XM's but i know it's almost double of the 20k XM.

i would leave it the same just change out bulbs if thats what you want. But i would also pay close attention to your corals and make sure they are aclimating to the new bulb ok. As well you will probably see a decent drop in growth from going from 10k to 20k

 

[DrBDC]

What wattage do you run? If running 175's I'd recommend the Iwasaki 15,000K's.

 

[Ti]

nah u won't get any bleaching.

 

[gemxsps]

10K has much more browning and bleach.
20K has less growth but great colorlation.

 

[jay24k]

The above post doesn't make any sense to me. 10K you get a true color and not brown or bleaching unless you go from 20k to 10k without acclimation. IMO, you get a better color with 10K then you do 20K. However, 20K is pleasing to the eyes so the color appears nicer. However, the majority of the corals that looked nice in a 20K tank did not look nice under a pure white light with 10K's. I had to have it color up to where it should be and then it looks great in both tanks.

 

[spankey]

I ran XM 20k bulbs over my tank and liked them. They put out a nice crisp blue white color and never had any issues with growth or coloration. As a mater of fact. I have been given a digi colony that was once blue, it was placed in a buddies tank and it turned brown under his 10k lighting. Since I took it the coral has turned a nice purple with bright purple tips.

I agree, 10k bulbs will get you great growth and nice colors, but a 20k bulb will bring out colors you won't see under a 10k bulb. The only reason for this is the color spectrum makes the coral flouresence more. The color is there its just harder to see under a 10k.....

Why the brown digi turned purple? I have no idea, I think the lights had allot to do with it, but I think everyone's tank chemistry is different! I have seen corals turn two total different colors under the same lights and wattage, just two different tanks? Go figure!

I have a small tank and thus went with color vs growth. I enjoy fragging but with three kids it was taking up alot of my time. I have since switched to a Phoenix 14k bulb and love the color. Good color and decent growth...

Its all in what the owner wants, bottom line.
Spank

 

[gemxsps]

jay24k

Under 20K the color of sps will be much better than 10K because in the real ocean only blue wave can go to the bottom of sea as other waves have been obsorved.
So real color of sea is like 20K. But sun itself is very intense.
So sps can get only intense blue color of light in the sea.
10K looks natural color of light but it can be artificial to the sps. Furthermore 10K is near with UV range wave so contains much more UV than 20K makes sps turn brown and bleaching.
I agree growth of sps is much better under 10K but color can not be compared with 20K.

 

[jay24k]

I'll just have to disagree. I've seen plenty of corals that looked very nice come out of a 20K tank and the true color is not the same under a purer looking white.

I will agree that 20K can make some corals look nicer and bring out more greens.

Recently, I've seen a few people with 20K tanks that look nice break them down and under regular lighting or a nice crisp light, the colors are just not there.

However, my opinion is, choose whatever spectrum that makes you happy. If I could get the growth out of 20K's and not as blue, I'd probably choose em too.

 

[ClubReef]

Thanks for your input folks. I'm glad to hear that bleaching is not a major concern.

I've been very happy with the growth of the 10K up to now but wanted to see what a 20K bulb will do to the coloration of my corals. My goal is to deepen the colors and I'll try it at the expensive of growth. I'll never know unless I try

Thanks all

 

[Stoney Mahony]

I am not sure where this argument comes into play but who cares if you can take a coral from 20k and put it under 10k and you don't see the same colors. ALL corals take time to adjust to different lighting. "True colors" are what the coral looks like growing in it's natural environment not specifically under 10k bulbs. Since corals of the same species can be found at a wide variety of depths, they are going to look different. After the first few feet of water your already at 15-20k. At 60 feet they are taking readings of 30-35k. Very rarely do you find anyone using straight 10k bulbs and no actinics. If you do use actinics, then you can't really compare 20k vs 10k unless you were to supplement the 20k with natural daylight bulbs. My point is that people complain about 20k being to blue and buy 10k and supplement w/ alot of actinics. I run 2x 20k 400w xm w/ no supplementals and its not that blue. Colors are awesome and I couldnt be happier with growth. I used 10k ushios for years and there is definately a big difference in the colors you are going to get. I even have some pics I will post tonight when I get home of the same corals growing under 10k and then when I switched to 20k. There is definately a noticible difference. Browns colored up within a month to beautiful blues. As long as you step up the intensity of the 20k bulb, you can achieve the same growth as 10k.(ex 250w10k w/ supp or 400w 20k w/o supp). Not meaning to sound negetive in any way here, just trying to get my thoughts out.

 

[jay24k]

My point was it is the same to your eye but if you put the coral under a pure white spectrum there is a big difference. It's almost like clothes, stick vertical stripes on a fat person and they don't appear as fat but they are still fat. I still say do what makes you happy.

 

[ClubReef]

Stoney,

I'm going to be running 250 watt 20K bulb for a 24" deep tank...hopefully this is enough intensity? Do you have any experience with this bulb? Also, I heard the 250watt version runs really blue, will turning off the actinic be ok for the tank?

 

[Stoney Mahony]

I ran 2x 250w 20kXM bulbs before I bumped up to 400. I admit, I have slight overkill but thats what I have to work with. The 250w 20kxm were noticably more blue than the 400w. I definately don't think you will be needing actincs for the tank though, I suggest getting your MH bulbs first and if it's not blue enough for your taste, add actinics. Personally, when I put actinics on my tank it was hard to make out the corals b/c it was soooo blue. Also, it depends on what species you plan on having in your tank. Acros love light and in my opinion will like 400's better in a 24 deep tank. The initial investement is more, more heat, bulbs cost the same, powers more, but I don't think you will need actinics so you save money there and the growth is amazing! Like jay24k said, it's definately about what makes you happy, I would just buy 1 piece at a time and if you don't like it, take it back . Take a look at the sps tank thread and check out some of the pics, im sure you can find a set up that looks appealing to you.