Best K rating for reef tank lights

[Fishfanatic]

I am going to be replacing the MH bulbs in my light and was wondering what the best lights are for coral growth. I currently have 20 000k bulbs and I have a mixture of LPS, SPS and softies. My tank is 30" deep so any advice would be appriciated.

[Zoaelite]

I am going to be replacing the MH bulbs in my light and was wondering what the best lights are for coral growth. I currently have 20 000k bulbs and I have a mixture of LPS, SPS and softies. My tank is 30" deep so any advice would be appriciated.

I believe that 6700k is natural sunlight, the best for coral growth is 10-14k and 20k is the best for showing corals.

Levi

[justinl]

the 6700 K is best for just growth but colour wont be very nice. 20000 K makes colours pop but growth slows down. anything in between is a compromise between growth and colour. Myself, I like 15000 K (no other supplemental lights), but what you proritize (growth or colour) is very subjective.

i dont know that i would ever call any light coming out of an artificial bulb "natural sunlight." That's like teh comparison of our tanks to the ocean; it just doesn't really compare.

[fencer]

I did a poll last month and most people were doing the 14k bulbs

[SeaHorse_Fanatic]

I have all 14000k DE 250w bulbs over my coral tanks. Aquaconnects on the big tank & Phoenix over my frag. Absolutely love them.

Anthony

[wickedfrags]

20K XM's on my display for about 3 years now.

[Zoaelite]

the 6700 K is best for just growth but colour wont be very nice. 20000 K makes colours pop but growth slows down. anything in between is a compromise between growth and colour. Myself, I like 15000 K (no other supplemental lights), but what you proritize (growth or colour) is very subjective.

i dont know that i would ever call any light coming out of an artificial bulb "natural sunlight." That's like teh comparison of our tanks to the ocean; it just doesn't really compare.

I really wasn't compairing the 6700K bulb to being "sunlight", but natural sunlight if im correct is at 6700K. Agree with the point about proritizing for growth and show though.
Levi

[BCOrchidGuy]

Natural sunlight at the equator at noon is 5000k when the equator is pretty much closest to the sun. As you move further north or south the colour temp changes. 6700k is daylight deluxe as sylvania I think calls it. Chroma 50s were probably (emphisis on probably) one of the first true daylight tubes, at 5000k it is a tri phosphor meaning it contained red/blue/yellow phosphors. Don't forget, what is rated at 10,000 by one company may appear just like a 14,000k that another company puts out. As was said, 6500/6700 is great for coral growth but it doesn't always look as appealing to our eyes.

Doug

[mseepman]

Doug,

I noticed in your signature that you show having 50,000k HOt5's....where did you get those bulbs if I may ask.

[fiorano]

im using 14,500k halides and t5's it looks pretty good and i hope that doesnt really slow down coral growth or anything

[Drock169]

I like 15K, still gives you good colour and the growth is decent

[fkshiu]

Any discussion of colour and growth potential with respect MH bulbs in purely general terms is pointless without reference to Sanjay Joshi's testing:

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

Choose your ballast, choose your bulb and off you go. PPFD (a.k.a PAR) and CCT (a.k.a. colour) are the most important columns. Actual power consumption in term of watts is useful as well.

Of course colour preference is purely subjective and mixing in supplemental lighting such as actinics adds to the choices you have.

Having supplemental actinics gives you more flexibility since you can use a bulb with higher PAR which are GENERALLY in the lower-K more yellow range.

[bv_reefer]

i get good growth out of my 15k's but the colors especially pop-put when the bulbs are newer

[BCOrchidGuy]

Mark I got them at Hidden Reef in Abbotsford, they are actinics but a bit different blue, nice light.

Doug