Par ratings for corals

[Jay1982]

Is there a thread or website which breaks down some optimum levels for certain corals.

EG: Bubble coral should be receiving "x" on the par scale
Acropora should be receiving "x" on the par scale

Its just that I sometimes get confused with "Medium lighting"
I find all the "high, medium, low" to be extremely uninformative and subjective. To some people a 60 watt bulb to be too much (ie: Mr. Burns reaction to homer putting in a 60 watt bulb in his office lamp. lol)

[BuddhaKiss]

yea it is pretty subjective isn't it. I'd like to know as well

[kb11235]

In my opinion, there is a lot more involved in the growth of corals than lighting. I can grow clams on the sand bed of my 58g with only 225 watts of VHO's, even though most people recommend much more intense lighting.

[Jay1982]

My corals don't have problems growing. But I'd still like to give them optimal conditions to thrive under. Its not just enough for them to be there. I want things in perfect health. I do agree that its more than just lights. But lights are a big factor non-the-less.

[greenbean36191]

Such information doesn't exist. Even for a single species it takes months of work. You have to make a light/depth profile at multiple sites throughout the species' range, then take individuals from the entire range of depths at each site and make a photosynthesis/irradiance curve. What you tend to find is that the saturating intensity varies tremendously between individuals of the same species and even within individuals over time.

The best you can really do is try to quantify what "high," "medium," and "low" lighting mean in an aquarium setting. Dana Riddle has done measurements in various tanks and breaks down his results like this:
very low- 15-100 umol/m^2/sec
low- 101-200 umol/m^2/sec
moderate- 201-400 umol/m^2/sec
high- 401-700 umol/m^2/sec

[Jay1982]

Ah, thank you. I was hoping to at least quantify what low, medium, high were at. Now I just need to find a Par instrument. There are no reef clubs in Montreal so I can't go to them to get one, and none of the reef shops around town use them...