PAR readings and light requirements ?

Discussion in 'Reef Aquarium Discussion' started by MAXreefer, Oct 26, 2010.

  1. MAXreefer

    MAXreefer Well-Known Member

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    I have been trying to find some info regarding the PAR numbers suitable for several kind of corals.
    I found this article: Classification and Terminology For Reef Aquarium Lighting

    Looking at the Blundell's Lighting Scale they came up with some kind of classification/scale (1-10) for corals:
    Scale PAR
    Low Light 0-4 0-400
    Medium Light 5-6 500-600
    High Light 7-8 700-800
    Very High Light 9-10 900-1000

    Those PAR numbers seems very high to me. For example a SPS coral with high light requirement would need PAR between 700-800.

    What is your opinion on this?
    For those who have measured the PAR numbers in your tank what numbers did you had on average?

    Thanks for any input
    Michael
     
  2. Troylee

    Troylee all about the diy!!!!! R2R Supporter R2R Excellence Award

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    I think we the people are more concerned with par than any coral to be honest.... I just move stuff around untill it's happy... If you know your corals and observe them everyday they will tell ya when there happy...;)
     
  3. mlove

    mlove Reefing Peasant

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    Ditto.
     
  4. MAXreefer

    MAXreefer Well-Known Member

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    I do agree with you guys but not everybody knows his corals that well. Agree also that observing is a big factor.
    At the other end some general guidelines could be helpful for those who are not so advanced in the hobby.
     
  5. Troylee

    Troylee all about the diy!!!!! R2R Supporter R2R Excellence Award

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    well i took some par readings with 250watt xm10k's and found 1600 just below the bulb 1200 at about 1" down in the water around 600 about 12" down and 300 on the sand bed 24" deep.... corals bleached and cooked from the middle up on a 8hr photo period....
    xm20k's i got 800 under the bulb about 500 1" down 230 about 12" down and 30 to 60 in the sand.... i kept montis in the sand with 30 to 60 par and they grew like crazy and colored up pretty sick.....
    i dont think you can tie a par number to any one coral to be honest.... there also a ton of variables involved in par readings.... bulb, ballast,reflector, water clarity being a major factor!!!!! i think the general rule which is pretty reliable is sps in the top 2/3rds of the tank and lps softies in the sand.....although that don't apply to every thing since i got a chalice cooking in the top 3" of the tank about 800 par with my radiums.... it's more of a observing thing in my world lol..... your question is really hard to answer....:(
     
  6. shaggy420

    shaggy420 Well-Known Member

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    true, i have a few different pieces of the same coral in different light and a lot of the time they grow faster in the lower light levels(300-500 par). I do currently have a setosa that is in 1100-1200par(when i checked with the par meter earlier this year, bulb was about 4 months old at the time of the test, now i have a new bulb in there so not sure on current reading) that is doing great. has that pinkish orange color to it.
     
  7. Troylee

    Troylee all about the diy!!!!! R2R Supporter R2R Excellence Award

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    my setosa hates light... up high guessing 1000 range of par it was bright pink but never grew.... mid way down 3 to 500 or so it's a nice red and grows pretty steady... just goes to show it's a tough question.... for instance i have 2 pink lemonade acro's in the display.... one up high "bright yellow" grows steady one on the opposite side down low green and grow's about the same pace.....i couldn't tell ya how many people have asked what those 2 corals are and look stupidfied when i tell them it's the same piece....lol :xd:
     

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