10,000K or 20,000K MH HQI???

[ALEXV]

Hi Guys,
I have a question that I havent been able to get a straight up answer...
As you can see at the bottom I have a standard rectangle 90 gl reef tank, I have about 4 acroporas, a porites, couple of pocilloporas etc..mostly SPS.....right now my two MH are 150 W and 10,000 K each, my question is this, I hear that the 20,000K bulbs give some corals a different hue or color tips....now my issue is this, does it matter that the tank will have a darker look if I put 20,000K bulbs? or to keep corals all it matter is the wattage? in other words will the SPS that I have will do as good under the 10,000K as they would under 20,000K ?
The main reason I ask is because I was told some corals actually show better coloration under 20,000K....

Please give some inputs....thank you.

[bertoni]

It's a matter of taste, really. The 20,000 K bulbs won't produce as much light for photosynthesis, which might reduce growth, but they do give a blue look, that some people like. I tried them, and am now trying 14,000 K bulbs. I like 14,000 K better, but that's only esthetics.

[Ti]

if u like it darker and more blue then 20k, if not then lower kelvin

[rjwilson37]

Some say that they still get the same growth under the 20k that they got under the 10k and some don't, but you will still get growth. I picked up a Acro stag from the LFS this past week and it was dark brown with purple tips under his 10k lighting. I have it under my 14k lighting right now and it has a sort of green, not dark brown color, but it still has the purple tips.

Your corals may change color a little, but your 10k does make things grow more and adds more to the Red's and Yellow's, and your 20k will add more to the Blues and Green and make things a little more flouresence, but does take a little away from the Reds and Yellow's.

Just like Bertoni stated above, he is trying the 14k's and likes them better.

I am only running 14k's with no supplimental lighting at the moment and I think maybe the 20k with your supplimental Actinic lighting may be a little to much on the blue side and you may want to go with 14k.

Good Luck on this, because lighting is such a tough choice with all the choices out there for us!

[jimbo045]

I think the 20,000 are too blueish. I would go with the 10,000s I use 14,000s which I think are nicer. JD

[ALEXV]

So I guess the answer is to stick with the 10k....the main issue was because I bought some color tip acroporas and when I got them one had the nice blue tips the other with purple tips and one with pink tips, but now the the bodies are brownish and the tips for the blue one look white, and for the pink and purple the tips look like the rest of the corals body.....even my purple plate, it looks more like pink..and my LFS told me that it had to do with the lights kelvin rate...I guess they say that 10k is like noon time and 20k is like 3 pm.., oh well.....I dont want to risk their health over their looks its a tough decision...would 14k make much of a differece comparing to 10k?

[rjwilson37]

The 10k is going to take some of the blue out of purple, which of course is going to make it more red/pink, and yes your blue is going to turn a little white. You not going to risk the health of your corals by switching to a 20k, or no one would use a 20k bulb.

Here is my tank under the old 11k lighting and again now under the 14k lighting. You be the judge as to which you like better. Look at the color of the Acro in the upper left corner under the 11k and now under the 14k. You have 10k, so your color is a little less. Heck the 6.5k turns everything brown.. brown.. brown, but they grow like crazy.

[rjwilson37]

First picture is Green Acro under 11k lighting, and the 2nd picture is the Green Acro under 14k lighting about 3 months later.

[ALEXV]

WOW..thank you for the input RJ, cant get any more detailed answer than that....I will go with the 20K....10Ks are just too bright.

Thank you again....my only fear was that my acroporas wouldnt like the darker hue, but you just proved me wrong.

[rjwilson37]

There is suppose to be some new bulbs called reeflux bulbs or something like that. They are a 10k but have a lot more blue to them and they are suppose to be really good. Melev who is an RC_Mod here on RC was trying them out, so maybe you could ask him. My tank was on the blue side a bit with the 14k until the bulbs burned in, and I don't use supplimental lighting, just the straight 14k MH.

This link here is to a fellow TOTM reefer who uses the 20k with VHO Actinic and he states that it looks great after they bulbs burned in and it did not effect his coral growth at all.

http://reefkeeping.com/issues/2004-01/totm/index.php

[szwab]

you will lose some par with 20k bulbs. but I think for the most part it will come down to aestetics if you don't like the results then switch them out in 9-10 months

[ALEXV]

Ok guys my last question about this subject....this is what I will have when I am done and you tell me

2 x 150 W 20,000K MH HQI (My ballast takes up to two 175W, but i cannot find 175 W HQIs) These are set up on the back of the tank - one fixture

4 x 65 W 12,000K Compacts set up on the front of the tank.-2nd fixture

Now here is the question, on the fixture with the MH, i have 2 x 96 W actinic bulbs......
can I replace them and put 2 x 96W 14,000K instead?...this would mean no actinic bulbs at all.....would this be ok..or do I need the actinic for the corals?

Thank you and I apprecite all the help!!!!!!!!!!!!!!

[szwab]

you would be fine doing what you have planned. I'm not convinced the corals benifit from actinics I think they are mostly pleasing to our eyes.