Lighting calculations

[Joe Reefer]

Lighting a reef isn't as simple as watts/gallon. Here are some links for you, hope this helps.

[Synthesis]

Calculation it in respect to watts/gal is a common mistake. It should be measured by intensity of the light being provided. Obviously we all know that placement of coral dictates the success of the it. This is because of intensity. SPS and LPS generally have to be high in the tank and almost strictly require Metal Halide bulbs. You can put them lower in the tank depending on the intensity of the bulb.

Soft corals such as zoos and mushrooms dont generally do well placed high in the tank and exposed to intense lighting. FOR PC and CF, the higher you place the corals the better as the intensity is not the same as MH.

I would read the link provided in the post above to help back up my statements. Lighting is a little more complex them most realize. Each tank is different and each coral has different needs. Sometimes they want alot of light and sometimes they dont. Trial and error is sometimes the only way to figure things out in this hobby.

[daddy01]

Well I went to the links one is broken, the others are beyond my comprehension...I left more confused than ever and none answered my question.
On other forum the general rule is x Watts per gallon and I emphasize general,
what I want to know is if that wattage refers to the accumulated wattage contained in fixture 65W 10000K daylight +65W Actnic 03=130Watts does it matter whether it is Blue actnic or Daylight.
Jim

[Kryten]

I would say if you're going to stick with the general watts/gal guideline then don't count the actinics.

[muck]

Actinic lighting does not have much useable light for your corals.

[Johnny Reefer]

Originally Posted by Kryten

I would say if you're going to stick with the general watts/gal guideline then don't count the actinics.

Agreed.

Originally Posted by muck

Actinic lighting does not have much useable light for your corals.

Agreed.

Actinics are for aestethics (sp). They bring out the colors. Think black light and those posters some of us had at one time.

Cheers,

[WWWD]

It also depends on the depth of your tank, deeper you go the less light penetrates below. Also keep in mind that the useful par value in CF lights are pretty much used up within the first 6 months of the bulbs usage. While they might fire and even look bright they have the same effect as floresent office bulb in terms light your corals need to grow.

I think others have mentioned that metal halides are the most cost effect means of lighting most tanks, you should consider that before you get locking into a lifetime of buying CF bulbs and wishing you hadn't.

[ron101]

Originally Posted by daddy01

On other forum the general rule is x Watts per gallon and I emphasize general, what I want to know is if that wattage refers to the accumulated wattage contained in fixture 65W 10000K daylight +65W Actnic 03=130Watts does it matter whether it is Blue actnic or Daylight.
Jim

As others have said, watts/gallon is such an oversimplified guideline that it is practically useless. What we are actually looking for is the amount of photosynthetic radiation, which you will see referred to as PAR, at the point where the coral is located.

Generally the higher the color temperature of the bulbs used, the less PAR they put out. So 5500K has more PAR than 10000K and 10000K has more than actinics, etc. So yes it matters.

[daddy01]

so Ron101 what you are saying that a 2-5500K bulb would be better in my situation?
I am retired and have limited funds to work with so am trying to set up a 'Nano' system using what I have at hand cause to install a Halide would be ((amongst othere factors (suspending, fixture)my wife etc )) out of the question.
Frustrated in Surrey!
Jim

[ron101]

Well 'better' is subjective... 5500K (actually 6700K - I dont think there are 5500K PC's) would probably give more PAR but the light would look fairly yellow. Not many people find that appealing. Personally, using all 10000k is about as white/yellow as I would want to go.

However for budget reasons, I wouldnt get into buying new PC lamps to experiment. Try out what you have with some lower light corals placed higher up in the tank and maybe start budgeting for MH down the road. People often sell single MH pendants in the classifieds for reasonable prices. Just my $.02.