Do I Have Enough Light? (SPS)

[MHG]

I have a DIY LED fixture and I am getting 500 PAR at the top of my rock work. My tank is about 60% SPS. I have had some growth issues but I think I have a good balance now and I am seeing better results... However, I have my lights running at about 75% and I have one hole bank of 12 XP-E's not even being used....

So since it takes about a week or two to damage a coral and about 7 months to recover one (In My tank anyway), I would rather not push it and see what happens...I would much rather get some opinions...

 

[MHG]

Evening bumpski....

 

[reefinsomnia]

What spectrums are your lights running?

 

[MHG]

I am not sure how I would determine that... I have a 2:1 ratio of Royal Blue XP-E's to Cool White XP-E's.

 

[MHG]

Evening bump

 

[reefinsomnia]

The Par is there but the full spectrum is not. One of the most essential ones your missing is UV (395nm - 415nm). For both amazing growth and colors you will need a full spectrum from 395 - 660. That is why you see led fixtures with red 660nm , green 520nm , yellow 590nm, blue 468nm , royal blue 442nm, along with UV and white.. For fast growth with so and so colors you will need atleast the four following: white, ultra violet, blue, and royal blue.

 

[gbru316]

The Par is there but the full spectrum is not. One of the most essential ones your missing is UV (395nm - 415nm). For both amazing growth and colors you will need a full spectrum from 395 - 660. That is why you see led fixtures with red 660nm , green 520nm , yellow 590nm, blue 468nm , royal blue 442nm, along with UV and white.. For fast growth with so and so colors you will need atleast the four following: white, ultra violet, blue, and royal blue.

FWIW, wavelengths greater than 400 nm are NOT UV. UV, by definition, is less than 400 nm.

The most popular single wavelengths are 420 nm (True violet), royal blue (455 nm), turquoise (495 nm), deep red (660 nm), supplemented with neutral/warm white emitters.

The deep red/turquoise combo will yield a 14k white appearance when combined.

yellow and green aren't very useful from a photosynthetic standpoint:

 

[danil]

The simple answer - yes. You have more then enough PAR to grow pretty much any SPS. Majority will need only around 200 PAR to grow with 300 being ideal and max out around 500 means no more growth will occur for an increase in light. These numbers vary from one coral to another and have pure scientific value. There is a way to measure it. Here is a little table. Unfortunately they killed the link so I just use my old copy of it.

Organism Genus Species Lighting Requirment PAR (µE m2sec)
Minimum Ideal Maximum
Anemone Anthopleura elegantissima 73 None @ 540
Coral Acropora cervicornis Medium 281 306 331
Coral Acropora digitifera High 82 327 600
Coral Acropora divaricata Very Low 10 77 200
Coral Acropora formosa High 170 340 600
Coral Acropora gemmifera High 170 340 600
Coral Acropora granulosa Low 53 107 450
Coral Acropora microphthalma High 170 300 600
Coral Acropora millepora (coenosarc) Medium 100 190 500
Coral Acropora millepora (polyp) Medium 140 230 550
Coral Acropora nobilis (coenosarc) 170 310 600
Coral Acropora nobilis (polyp) 100 180 500
Coral Acropora Species Medium 131 246 503
Coral Cyphastrea serailia 100 150 200
Coral Cyphastrea Species 100 150 200
Coral Montipora capitata 135 193 250
Coral Montipora tuberculosa (coenosarc) Low 130 180 250
Coral Montipora tuberculosa (polyp) 100 300 400
Coral Montipora Species 122 224 300
Coral Pocillopora damicornis Medium 150 225 400
Coral Pocillopora eydouxi High 250 323 425
Coral Pocillopora meandrina 275 350 425
Coral Pocillopora Species 225 299 417
Coral Pavona varians Low 110 230 350
Coral Pavona Species 110 230 350
Coral Porites cylindrica 150 200 250
Coral Porites lobata Medium 250 300 350
Coral Porites lutea High 400 575 750
Coral Porites Species 267 358 450
Coral Sinularia densa 207 304 400
Coral Sinularia Species 200 300 400
Coral Stylophora pistillata (Shade) Diverse 40 200 600
Coral Stylophora pistillata (Light) Diverse 40 300 600
Coral Stylophora Species 40 250 600

 

[gbru316]

The simple answer - yes. You have more then enough PAR to grow pretty much any SPS. Majority will need only around 200 PAR to grow with 300 being ideal and max out around 500 means no more growth will occur for an increase in light. These numbers vary from one coral to another and have pure scientific value. There is a way to measure it. Here is a little table. Unfortunately they killed the link so I just use my old copy of it.

I'm afraid it doesn't quite work this way. PAR is merely a single variable when dealing with the lighting requirements of a particular coral.

Numerous other factors are equally important, including spectrum, nutrient load, water flow, temperature, particulates, photoperiod, etc. One cannot simply ignore these parameters and focus on PAR.

At some point in the late '90's/early 00's, we started focusing solely on PAR (IIRC, around the same time Dr. Joshi started doing his lighting analysis) as the most important aspect of aquarium lighting. Research since then has shown that this methodology is erroneous and is only a part of the equation.

 

[MHG]

The Par is there but the full spectrum is not. One of the most essential ones your missing is UV (395nm - 415nm). For both amazing growth and colors you will need a full spectrum from 395 - 660. That is why you see led fixtures with red 660nm , green 520nm , yellow 590nm, blue 468nm , royal blue 442nm, along with UV and white.. For fast growth with so and so colors you will need atleast the four following: white, ultra violet, blue, and royal blue.

Well thats exactly why I ask. I was planning on filling in the spectrum...I have a full segment of 12 whites that I am not using. I was thinking of replacing them wuth the UV... I have 3 of the UV's on my front fixture that is lust their to fill in a shadow caused by the rock work.

I was also going to add 3 red and 3 green led"s but I need to buy more drivers for that and build a whole new wire harness. Its on my list...

 

[MHG]

I'm afraid it doesn't quite work this way. PAR is merely a single variable when dealing with the lighting requirements of a particular coral.

Numerous other factors are equally important, including spectrum, nutrient load, water flow, temperature, particulates, photoperiod, etc. One cannot simply ignore these parameters and focus on PAR.

At some point in the late '90's/early 00's, we started focusing solely on PAR (IIRC, around the same time Dr. Joshi started doing his lighting analysis) as the most important aspect of aquarium lighting. Research since then has shown that this methodology is erroneous and is only a part of the equation.

Thanks for the input. I do appreciate it...I am not claiming PAR is the end all be all...I was just asking if I have enough light. I have lots of threads on the other topics... Since PAR is essentially the only measurement a basic hobbyist has, that is all I can offer as a reference... As I am considering enhancing the spectrum, I would take the answers to my question into consideration when planning. So if people say you need more, then I would add the spectrum with little concern over balancing the PAR with my existing ligts to keep the PAR where it is. If people say, you have too much, then I would make sure top lower my existing set up when I add the additional spectrum...