MH bulb

[marinereef]

Hi.....

I am using 20K MH bulb for SPS coral presently....just wondering which is better for growth and colour??

A 10K or 20K Mh bulb??

Pls advise from the SPS reefer here.

A million thanks !!!

[ryz]

10K is better. more PAR. 20K more for deep reef corals etc.

IMO

[marinereef]

I have the same idea 2

Just to have more reefers opinion...pls comments

Thanks

[AlfaRomeo]

Why dunt you try the newer 14KK bulbs? I think its a compromise between the 10kk and the 20kk logically...

[Achilles Tang]

In the order of the highest PAR levels,

6500k

10,000k

20,000k

As you can see, the bluer the bulb is made, the more PAR is lost.

The 6500k bulb is the best as it is full spectrum as opposed to only having spikes in the blue spectrum like the higher k bulbs. It gives the best growth and possibly colouration (for most corals). Just too bad that its visually too strong in the yellow/green area to the human eye. In reality, the 6500k bulbs have very strong blue spikes, equally more or less the higher k bulbs.

I use the 6500k Iwasakis in combination with 20k and I get a pleasing white and the best of both worlds so my SPS corals will benefit from it.

[DeepBlue]

hmmmm.....good info.

[Achilles Tang]

Deepblue... you saw my lights.... nice blend?

[marinereef]

I can imagine it is a good blend 2...btw is there any different in light intensity for the different kelvin in bulb?

[Achilles Tang]

The higher the wattage of the bulb, the higher the light intensity. Is this what you're asking?

A 6500k bulb is also visually brighter than a 20k bulb if they are both the same wattage.

[Jackson6745]

I have heard great things about this website and I plan on learning as much as possible as well as offering any knowledge that I have of the hobby.

IMO if you're going to go with 20k's you MUST go with 400w unless you plan on keeping all your SPS near the top of your tank. When I used to run 250w Radiums The only corals that would actually keep decent color were the ones that were 6" from the bulb. Now I run 250w DE Ushio 10k's and get better color, growth, and I can place many species from mid to the bottom of the tank and still have nice color.

Here is an old pic of a 250w Radium compared to a 250w 10k XM. Both bulbs are run on a pfo HQI ballast. Looks like the radium isn't even on Sorry for the poor quality pic

[Jackson6745]

and here is a comparison of a SE 250w 10k XM vs. a DE 10k Ushio. The double ended ushio is so much brighter

[ervine]

I don't really like my BLV 20k... it's WAYYYY too blue... makes all the colours fuse into one.. either that or the bulb hasn't burnt in fully yet..

[islander]

couldnt agree with u more ervine...the 20k..is like a combination of 10k plus actinic that went wrong!might 1 2 change.....

[Achilles Tang]

Hi Jackson6745

Welcome to SRC!

You're from the US right?

[Jackson6745]

Hi Jackson6745

Welcome to SRC!

You're from the US right?

Yes, I'm from New York. Achilles I checked out the thread with your reef all I can say is.....WOW. I would live to see that in person!!!

Anyway, thanks for the welcome

Rich

[DeepBlue]

Deepblue... you saw my lights.... nice blend?

yup...love the look of it

oh yah, welcome to SRC, Jackson6745.

Seeing AT's tank does make pple want to try SPS.... evil evil tank which makes the pockets burn deeper!!!

[marinereef]

The higher the wattage of the bulb, the higher the light intensity. Is this what you're asking?

A 6500k bulb is also visually brighter than a 20k bulb if they are both the same wattage.

Probably I will try on the 6.5K bulb....btw where to get this bulb??

Pls give advise.

[surfedelic]

Just wondering whether we can use those energy saving bulb eg. 20W = 100 watt type compact lamp. I mean those with color temp of 6k to 6.5 k. Maybe put about 5 bulbs in there and compliment it with a 20K MH.