Optimum PAR Levels for Coral

Discussion in 'Resources' started by Nav, Jul 9, 2014.

  1. Nav

    Nav Director of Marketing & Photography

    Its my turn on the PAR meter but before measuring, I wanted good resource listing all coral with the optimum PAR levels.

    Lots of google searches only took me to forum posts where people shared their opinions on a few coral. Then I found a microsite built by bluemoonaquatics where they had a full list of coral with the PAR ranges.


    Problem was that the site was unusable with an overlay that I couldn’t close. So I took screenshots of each subsection and compiled it into a PDF.

    Hope its helpful :)

    denzil likes this.
  2. bluprntguy

    bluprntguy Webmaster

    denzil, gunit and Nav like this.
  3. aqua-nut

    aqua-nut Supporting Member

    Thank you both for gathering this info. I think.

    It's confusing. One chart lists max PAR at 800 (AA), one at 900 (A-A) and the last at 900+.

    The Advanced Aquarist article has a very confusing 0-10 vs 0-1000 range that doesn't seem to agree with itself. The first three, Stylo thru Acro are listed as 4-10 or 700-1000, 600-900 and 600-1000. Might as well say medium to high.

    If there is a definition of low-medium-high that would be a simpler classification since the ranges seem so broad.
  4. sfsuphysics

    sfsuphysics Supporting Member

    Well the AA article isn't a matter of disagreeing with itself, the 0-10 is Julian Sprung's values, the 0-1000 are PAR values that were reported by aquarium owners, so two separate sources.
    However that said, I think that's exactly what they're saying "medium to high" lighting... but the question of what constitutes "medium" is where the numbers come into play.

    Considering most aquarium owners don't have access to a PAR meter, what they judge as "high" might be far from the truth as far as "high" lighting. Hell even the older version of "should have at least 250watts of MH ..." is too ambiguous since there are different color temperatures which affect light output, and even amongst similar color temperatures you can have a wide range.

    Either way, if you do have access to a PAR meter you can figure out if your LEDs (or any other light) should be "sufficient" enough to keep corals. Although I have to say I have kept acropora corals on the bottom of my tank in conditions lower than what is stated.
  5. bluprntguy

    bluprntguy Webmaster

    Since this evolved into a discussion on optimum PAR levels, my experience is that these listed values on both the PDF and the AA article are probably higher than they should be. In about 6 feet of water, light levels in most coral reefs drops to 600-800 PAR at high noon on a sunny day. If you factor in weather, the change in the sun angles on either side of noon, tides, etc, I'd be surprised if many corals out there in the ocean see PAR values consistently over 300-400 PAR over the course of the day. If you look at the "recommended" column of the Arcadia list that I linked, you'll see that that's unsurprisingly about the range where their numbers fall.

    I'm pretty sure if corals could talk, we'd hear most of them screaming for us to turn down the frigging lights already.
    Geneva likes this.

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