I think everyone has a ? about Lighting!

[berger034]

My question is: what is up with all the kelvin. there is 5500 and 6500 and 8500 and 10000 and 20000. is it not like the old saying goes for filtration, more is better? where is my malfunction in this mental process. i am stumped. cant i just put 3 250w mh's, 3 actinics vho's and 3 daylight vho's. i know there is an issue with the electricity bill but if i had the money wouldnt this be the best possible answer?

[Nanook]

LOL....I hear ya on the choices.....what to do, what to do. I change my mind daily on lighting choices. I think it depends on a few factors: What corals do you intend to keep? What amount of money are you willing to pay for electricity each month? What amount of money are you willing to spend every year on bulb replacements? Finally, what coloration do you like in your tank?

I am planning three large tanks where all these factors come into play, unfortunately, I have to strike a balance on what I can afford to run and buy each year. In the best of all worlds, money is no object and you can experiment with as many combinations as you like and see what happens. I think our lighting reproduction pales in comparison to the ole SUN. Good luck with your decisions! BTW, what are you trying to keep?


Nanook

[Nanook]

I am not sure if you wanted the differences in MH kelvin temps explained a little or not? The 5500K and 6500K tend to resemble the suns color, perhaps a little warm or yellow to the eye. In comparison, the 10Ks appear white, while the 20Ks appear bluish white. I like the 6500K Iwasakis for growth and PAR/PPFD values, but the blue coloration of the higher kelvin bulbs combined with the Iwasakis is a nice mixture. 6500Ks by themselves are a little too yellow to my eye. Even the 10Ks without VHO actinics are too plain white....I prefer a touch of blue to the lighting. If you can see some reefers tanks in person to evaluate the different options, you would save yourself some time and money in the long haul. I have bought most of the bulbs available and still search for a better combination.


Nanook;)

[David Grigor]

My advice ( Basically same as what Nanook points out ) :

First off, there is NO perfect bulb. All have pros/cons. Some are better than others for a particular coral but not necessarily for all. Personal preference to the color also play a major role in your decision.

You have two ways to determine what best for you. First and most expensive is trying lots of different ones until your find whats best for you. I have been in the hobby since 96 and have tried lots and lots of combinations and of course spent lots and lots of money.

Second and most wise is to get hooked up ( if your not already ) in a Local Reef Club. While I can't speak other clubs but our local club in the Twin Cities, there is such a wide range of tank setups locally that you can basically see for yourself lots of different lighting types as well as different K bulbs. Pay attention to what corals they have in the tank and how you like the overall look.

I really don't recommend putting too much stock in tank pictures viewed online when trying to make a final decision. Usually tanks pics with lower K bulbs are take better pictures than the higher K becuase camera tends to overexaggerate blues. I have seen some great looking tank pics and to be honest quite disappointed seeing the tank in real life. So I wouldn't base solely on online pics.....

[Creade]

I just saw a lighting website with all the different K bulbs in different brands all shown side by side in comparison as to how they look, god i should have book marked it. Something for me to go find. Ill link it soon as I can find it again.


Creade

[moonpod]

essentially the lower the color temp (kelvin) the yellower in appearance, the higher the bluer. the number is representative of a certain shift/spike in the color spectrum of the bulb. 6500k is theoretically closest to the full spectrum of the sun. In practice this is where people who advocate the iwasaki 6500s come from. This appears very bright and some things grow best under these lights, especially shallow reef things. the thing is aesthetically, 6500k is very yellow and most people find unappealing. Hence the popularity in general of higher kelvin temp lighting. In contrast, though the 20000k bulb is still producing however many watts of light, it will appear dimmer than a 6500k b/c of the bluer overall light spectrum. There was something published earlier which showed how different inverts grew better under different kelvin temps, with I think (could be wrong) SPS growing fastest under higher temps, coralline for instance doing better under lower color temps along w/LPS. softies were inbetween I think as were clams. As I recall, everything grew under all color temps, but some things were faster under different color temps. Again, could be wrong. Anyway, in practice, you get the bulb/combo that gives the "look" that you individually like. Most things will grow under anything 6500k and up.