What spectrum halide for a grow out?

[bridun22ajl]

hi,
I'm looking for advice for a grow out tank. I'm using 400w mh and wondering if people still recommend using bulbs like 6500 or 10k bulbs for growth. I have read some stuff where people recommend using bluer bulbs(14k, radiums, etc) because the corals need the blue spectrums also to promote growth. Is this true? Is using 6500 or 10k bulbs an 'old school' way of thinking? If possible post links to back up your thoughts.
thanks in advance
Brian

 

[Bryan]

For max growth I don't think u can't go wrong with Iwasaki 6500K. Yellow as heck, but growth is great.

 

[bridun22ajl]

I have read that the acros need more then just that spectrum and the blues will actually help too... Is this true?

 

[allsps40]

I have great growth with 20ks. But If I wanted to really grow corals like crazy I would use 10k or 14k.

 

[intoodeep]

I think there is data to support that the Iwasaki 6500K bulbs have a substantial dose of the blue spectrum in them. I don't care for aesthetic of them but they apparently suit their intended purpose. Sanjay's lighting page on Manhatten Reef should have some helpful information for you.

 

[stevedola]

I think the 10k ushios are supposed to be good for growing. I ran 6500 bulbs in the past for grow out tanks and its just too ugly and shifts colors of coral. at least the 10k isnt bad to look at.

 

[polywise]

lower kelvin grows faster, but when you get to a size point you will want to color up the coral, and I think that takes too long once you ahve gottent to where you want to be (size) . I prefer to keep them closer to desired color as they grow

 

[rtbm]

65k iwasaki's on a 250 hqi ballast is actually much whiter than a xm 10k, on a standard ballast. 400's on electronic ballast might be yellower though. I have never used 400's

but the 250 's on m-80 ballasts has one of the highest par of any 250 bulb ballast combo

The iwasaki is an incredible bulb. Corals will achieve unbelievable colors under them They just wont fluoresce like under a bluer bulb. Looks very natural in fact.

What ballast's are you running?

 

[blakers82]

I have read that the acros need more then just that spectrum and the blues will actually help too... Is this true?

It appears that Acropora growth will be higher with a halide bulb that carries a higher par rating. The 6500 and 10K bulbs mentioned have a good jump in par on most higher K rating bulbs (per Sanjay's extensive testing). Now coral colors is a debate, but it's safe to say in general, corals "like" good par and you get that with those bulbs.

 

[allsps40]

IME 6500k is more for fresh water planted tanks. 10k will give you great growth with decent color, 14k will give you better color. 6500k is very very yellow while it will grow sps very well colors tend to be on the duller side.