Lights MH vs T5's when it comes to actinic.

The whole color temp. rating (K=kelvin) 6500K represents natural sunlight which is shallow reefs. 20,000K is much bluer becuase it represents much deeper depths in the ocean which is natural. In theory if you had light loving corals, then you need white to almost green on the kelvin scale which natural sunlight at 6500K is on the greener side of the scale. If you had mushrooms, (in general) are less light demanding, so in theory you would need to be bluer, but since we are just replicating the natural reefs, and usually at depths less then 24"s, its all up to the aestitics of the reefer. Bluer colors at 24"s or less has almost the same intensity as 6500K. The downside to using 6500K even though you can get increased growth(but not always) it tends to washout the colors of corals, whereas the bluer colors really bring out the colors in most corals.

Like tangie said, "you show me one study that says one thing, I can show you 2 that say somthine else". Its like I always say..."opinions are like arseholes, and everybody has one and its usually different."

 

mh question

i just bought an Odyssea MH 250watts-20,000k bulb like i said its to much white. live rocks that are not cover with purple algae its showing green rather than a darker gray or black. i really want a right bulb to make my corallline algae purple live rocks to really show the dark color and not have any green thats not cover with the algae.for Odyssea Mh do you think the 10,000k is bluer than the 15,000 i will go buy one today. i used a Odyssea compact i think its a 96watts-12000k and actinic 65watts i took it out from my another tank and put it on to the one i using a Mh and the coloration is just right showing lots of purple algae and no green showing area where there no purple growing. which one should i use for 15k or 10k?

 

Coraline algaes dont tolerate metal halides very well. Coraline actually prefers actinic lighting and is found in abundance at deep depths where there is less white light.

 

Wow I got a tiger by the tail,or several of them lol.Take it easy on an old man lol.First let me say that there is no such thing as "white" light,we may percieve it as such but it is a combination of colors in a specific balance that appear white.
6500k light only has a small percentage of blue in it and that level of blue dicipates with depth and can not increase to 10,14,or 20 k levels.By the time light gets to the 20k level as produced by mh lighting it is almost totaly blue.But it does not and can not exist at those levels in nature.
Since corals have exited and evolved over millions of years under a constant 5745k natural sun do you think we can improve on nature by pumping up the blue?
Two of the articles I read were by Ron Shimeck and Anthony Calfo,I think they have been on a reef or two.

 

Well all I can say is if you ask anyone who cultures corals daily about the difference they will tell you K's equal different colors . As does the Actinics and I have found the URI VHO do a much better job of that then P.C or the T-5's I have them all running daily here. As for Dr Smuck LOL Guy is a educated idiot .
As I said I have corals here under 14 K 10 K 6500K 20 K and natural sun outside and every lamp develops a different coloration on the corals you'd swear they where different corals all together I would had I not grown them up from Pup's But that have been said I could care less about what people run and I'd not take Dr Smucks advice on what direction the sun rises ..

 

Now you're getting into physical science, not biology. There is natural white light.

As for reefs, yes, the sun is the natural light for it, but once you factor in the water+various depth, you get a whole another configuration on color temp. The deeper the water, the darker the water, thats common sense. If you dive in 1 foot of water, the visible light is going to be whiter then 30 feet. #0 feet is going to be bluer. No offense, but I wouldn't be listening to somebody who has a degree in english lit. and not marine biology.

 

algae question

i placed my tank next to a window and theres direct sunlight to the tank will it caused green spot algae growing because i had alot of purple algae growing before later the green took over the purple algae which is coralline and purple die off. my water is calcium 500,kh10,nirate .10,ph 8.0 temp 78. if it is the sunlight i will cover the tank. do you think the purple will start to go back again i like the coloration. what should i do?

 

Your calcium and KH is too high IMO. Calcium should be around 450ppm, and KH should be 2.5-4meg I think. If you're talking about DKH, 10meg is good, as it should be inbetween 7-11meg.

The sunlight is whats causing the green algae to grow, cover that part of the tank or close the blinds by it. When the conditions are right, coraline will make a come back.

 

I would love to continue this conversation,but name calling is usually the last resort of someone who has nothing else to say.

 

If I could add my two cents, the lighting you desire is what you should ultimately go with! Yes, their are studies and observations and such, but ultimately you are the one who has to look at the lighting scheme! Moreover, you have to decide on the corals you plan on keeping or the corals you have already and go from there as to which lighting will be best for you and what you have in your tank.
Everyone has their own opinion and experience! NOw, whether you decide to go with that or not, is up to you!
All I know is that if you use light that is closer to the red end of the spectrum, algae(micro) will grow quicker as nuisance algae loves that color light!