MH bulbs

[skaterzero22]

can i have some opinions on which bulbs to get and which to say away from for a 250w single end setup.

 

[smcdonn]

I love my 14K hamiltons.

 

[skaterzero22]

ok. what is the difference between SE and DS(i think thats what it is)

 

[skaterzero22]

sorry figured it out. any other suggestions?

 

[bramjansen]

Make sure you get a 15k at the least if you like it more blue/white. A SE 10K o a magnetic prodcues too much yellow for instance. Unless you hae T5's in addition, which I did for instance, to get more blue(or white).

 

[skaterzero22]

i have actinics i'll use with it but i also use an electronic ballast. and i would like more blue than anything so if that helps with suggestions.

 

[bertoni]

This site has a lot of data on bulbs:

http://www.reeflightinginfo.arvixe.com/

ReefKeeping.com also has some introductory articles.

Choosing bulbs has a lot of personal taste involved. A lot depends on whether the system has actinic bulbs along with the MH, for that matter.

 

[skaterzero22]

thanks bertoni

 

[Aquarist007]

yeah--thanks Bertoni--I been looking for that site for awhile

 

[bertoni]

Oops, we posted at about the same time...

If the system has actinics, you might try 14,000 K bulbs if you want a lot of blue. 20,000 K bulbs, and the tank might look like a deepwater system. I'd probably go with 6500 or 10,000 K bulbs, but I am not doing the deep blue look, currently.

 

[JENnKerry]

I read that the corals will grow at a much slower rate with a higher K rating. Can anyone confirm this?

 

[bertoni]

The higher temperature bulbs do tend to be less efficient, but there's a lot of variation. The site has a lot of hard data.

 

[chaseracing]

<a href=showthread.php?s=&postid=11591581#post11591581 target=_blank>Originally posted</a> by JENnKerry
I read that the corals will grow at a much slower rate with a higher K rating. Can anyone confirm this?

I am pretty sure it is the other way around. The 20K get great growth rates. The 10K's are very white, and the 20K are very blue. This doesn't mean you can't get good growth out of a 10K. The XM 10K paired up with an ARO elec ballast puts out a very high par rating which excellerates growth. I had those on my tank for while, but ended up removing them because they were too yellow for my liking. I am now using the 14K Reeflux and I think they are perfect. I even removed the Actinics I had.

-=E=-

 

[seapug]

It depends on the brand and type of bulb. A 20k by one manufacturer may look like the 14K from another. It is true that higher K rating bulbs have less PAR (photsyntehtically active radiation) but tend to look a little more pleasantly blue. I went through a "blue period" but found the growth was weak and the blue color made everything look the same. I recently swtiched to 12K Reeflux bulbs on my DE fixture and I'm very happy with them.

Just remember single ended (mogul) bulbs tend to look more yellow than DE (double ended bulbs) in general but it really comes down to personal preference so be prepared to try a few different brands and types. It's fun (if not a little expensive) to switch out bulbs and see how it changes the look and growth of your corals.

I have recently seen some tanks lit with mogul base 14K Ushios that looked really nice-- a good clean white light with a touch of blue at the point where 10k's tend to look yellowish.

 

[bertoni]

I've never seen a 20,000 K bulb described as great growth. My Hamilton DEs certainly were dim. The whiter bulbs tend to be more efficient, in general.

 

[BangkokMatt]

<a href=showthread.php?s=&postid=11594867#post11594867 target=_blank>Originally posted</a> by bertoni
I've never seen a 20,000 K bulb described as great growth. My Hamilton DEs certainly were dim. The whiter bulbs tend to be more efficient, in general.

Agree
General rule - High K equals coral 'pop' (color)
Low K equals coral growth
When a 20k with a massive par is produced it will be on my shopping list

 

[skaterzero22]

i decided to go with the hamilton 14k because i wanted decent growth and a good looking color. i figured this would be somewhere in the middle. thank you for all the information

 

[Aquarist007]

Now I am confused here guys-----
do 14000k or better halides promote growth and colour in coral?

it seems like there are two arguments going on?

 

[seapug]

Best growth comes from lower temp lights-- natural sunlight at noon at the water surface in the tropics is equivalent to about 5500K. There's more PAR at that level so growth will occur faster, but that kind of light on a tank will be very yellow.

As far as "better color" is concerned, it's a matter of opinion. Some people like the pee yellow look, but most people find that a bluer color is more pleasing to the eye. After using 10k's , 12k's, 14ks' and 20k's on my tank, I think something in the middle with actinic supplementation works best. I definitely don't like yellow, but 14's and 20's with actinics is just too blue for my tastes- -it makes everything look a little washed out and growth slows to a crawl in my tank.

I'd go with 14's if you have no actinic supplementation and 10K or 12K if you do have actinics. I've found that gives the best balance of growth and color.

But again, it's really a matter of personal opinion.

 

[bertoni]

If you go to the web site, the bulb, ballast, and reflector combinations that produce the highest PAR in the tank will produce more growth, up to the limits of the species of coral in question. The most efficient bulbs are still the Iwasaki 6500 K, I think, but a few others are close. The color temperature of a bulb isn't all that good a predictor of efficiency, although the higher color temperatures <b>tend</b> to be less efficient.