20K Bulbs

[Funkyskunk]

Hi there everyone,

Please can you give me the pro's and con's about a 20k bulb?

I will be mixing the bulb with 2 other 14k and 4 t5 3 blue one white.

I have heard very mixed reports about the 20k and am just not sure, good colour, slow growth etc.....

what is the real deal?

Thanks

[7thheaven]

I used XM20K 250w with no supplement.

You know good color, and slow growth is right...

and It is OK but 20K looks dim to my taste. so I changed it.

HTH

[moonpod]

OK first point of reality: most 14 and 20k bulbs are in reality much, much higher color temps than that. Off the scale meaning greater than 30k. There are a few "true" 14k bulbs, but the most popular "14k" bulbs are nothing of the sort.

In general, you get a "bluer" look to the tank that enhances certain colors with 20k bulbs. Also some 20k bulbs have very large 420 and 450nm spikes that make the corals fluoresce without needing supplemental actinics. The price is that in general the output overall is half of what you get with a generic 10k in most cases and that causes slower growth. There are exceptions, but this is the generality.

[Detritivore]

dont wanna hijack this thread, but wat about mixing say, a 10k and a 20k? would the color be more on the 10k side(since 10k is visually brighter), the 20k side(since...i dunno), or more in the middle, like 15k(since...its the middle?)

[moonpod]

It's hard to do well. With SE it's easier, but you usually end up doing some weird thing with your reflector. With DE it's hard to blend well. I've tried.

[Detritivore]

wouldnt certain corals do better under different K temps?

[moonpod]

mostly has to do with what the coral is acclimated to IMO. Then again, it's not like I'm some sort of coral maven.

[Orion76]

wouldnt certain corals do better under different K temps?

Most of the brightly colored SPS us Zeoheads like to keep live in knee-deep crystal clear water where the light they get is probably around 5500 to 6400 Kelvin.

[Detritivore]

thats weird, then how come 20k's are so popular?

[Orion76]

If you guys check out Sanjay Joshi's reports you'll find that in terms of intensity the bulbs marketed as 14,000K and 20,000K are rather similar and 10,000K bulbs have nearly twice the intensity as bulbs sold as 14,000K bulbs.

If intense lighting is your goal then IMO it's best to build your system around 10,000K bulbs and add blue bulbs to improve aesthetics to your liking.

[Orion76]

thats weird, then how come 20k's are so popular?

Because 5500K bulbs make your tank look like the incredible hulk peed in it, most people prefer smurf pee

[skeletor]

has anyone tried the 20K Helios bulbs that RM sells ? I was thinking of trying one of the 157w SE's..

I've only ever tried the 20K XM and I really miss the colours I had with that bulb. 14k looks nicer in the tank but I just can't get the colours I want.

rich.

[nyfireman3097]

i have used a few diffrent brands and temps right now i have 2 10k xm on the outsides of my 125 and a 20k xm in the middle where the 2 temps mix it looks aweomse the 10k color to me is perfect i only run them for 4 hours aday and my 20k i run for 12 hours i luv the colors and the growth is amazing once i hear a lil more on the 15k xm tht just came out today ill try them also HTH
Nick

[CurvBall]

Hey Christiaan,

I went from a 5500K osram 150w MH to a venture 18-20K bulb and although the colour is awesome with the 18-20K, my corals growth almost stopped The light produced is very 'soft' to the eyes and defiently lacks the intensity, at least visually, that the 5500K bulb had. I'll be running 10K 250w over my new tank supplemented by actinic T5's. For my frag tank, I'll run a 150w 5500K bulb just for growth.

HTH.

[GTR]

This a reply from Thomas Pohl in the German Forum.
Naja und deine 14000K Brenner solltest du auch entsorgen, die taugen höchstens für die Nachtbeleuchtung
im Schwimmbad.

Run through online translation...

Naja and your 14000K burner you should also dispose, those are at the most suited for the night lighting system in the swimming pool.

from this thread...
http://www.zeovit.com/forums/showthread.php?t=1965


SteveU