Light calculation?

Do you include the blue light watts into the total watts per gallon?

 

honestly, there is no watts per gallon calculation. watts is how much energy the bulbs use, not how much usable light they produce. with all the different types of bulbs and different efficiency levels PAR(Photosynthetically Active Radiation) is what should be taken into consideration. unfortunately, PAR measurements for specific bulbs are quite difficult to find as they depend not only on the bulbs but the light fixtures reflectors. the best way to find out how much and what type of light you will need, IMO, is to ask here stating your current lighting, dimensions of your aquarium (depth too), what types of coral you currently keep and what you intend to keep. the responses will be strictly what is working for experience reef keepers. if it works for them, it should work for you!

 

+1 best response I have read to this question.

 

My tank is 48L24W30D. I have done some looking in to the lights and have decided that T-5's wont make it to the bottom. And MH are cheap to buy but hard on the pocket book to run. So i have decided to build a LED fixture. I have about a year before the tank goes up so i have tome to work on one. Im hoping to keep a variety of corarls and such, in a community tank. But i havent see anything about the Blue lights. Is this just to make the colors pop out and be more vibrant or do the fish and coarls need this spectrum?

 

all spectrums of light are needed for photosynthesis of corals. fish do not need lights other than ones to make them look nicer.

Blue is one of the most important spectrums to have because a majority of photosystems use the blue wavelength. not only does the blue wavelength get used, but it also makes corals "pop" because when they use any wavelength for photosynthesis, sometimes they re-emit the photons at a different wavelength (thus a different color) so that is what you see as the "pop". blue is just the most abundantly used wavelength in coral photosystems, UVA the second most, and then typically violet, red, yellow, then green

 

Glad to hear you are going the DIY LED route. fully customized, expandable and fun to make! be sure to record everything you do and show us pickchurs!

 

To add to that, not all corals use the same wavelengths of PAR. So you could have alot of par and still have it be improperily lite.

really the whole lighting method in this hobby is a crap shoot. I still use wpg gallon method, but only with halide and t5's. Every so often someone tries to tell me off and tell me I need to use lumens, but those are almost just as bad as watts only harder to find out. I would be all for the PAR method since its so much closer to what we want to know, but it's almost impossible to find out that information and will continue to be that way.
So yea when people tell me I use a outdated system I just laugh ;D

chlorophyl light absorption chart for your amusement

 

well for example on both of my 55g tanks, I have around 7wpg.

first tank with 4xpc's/2xt5's/lunars

second tank has 2xmh's/8x3wleds/lunars

second tank can support sps/clams easily, first tank barely.

 

I plan to do a write up of my LED project. Im just gathering information right now. I just dont know what colors of leds i need to get just yet. Ive seen Cree cool white and royal blue's being used. But i have a little time before i start gathering parts up.

 

Buy cool whites that can be tuned to 10000K light spectrum. It will give you better color. Spectrum lower than that seems to wash out the color but give great growth.