PAR and SPS

[Rockys_Pride]

I'm wondering if there is a set amount of PAR that certain species grow best at. I found a table on here once, but I can't seem to find it again. Reading through the threads I'm finding that most people vaguely say, they all need different lighting requirements. I'm trying to find those requirements.

EDIT: found it. Is this still accurate? Table was not made by me, instead a far better RC user than me.

 

[meshwheel]

RP,
Looks to be fairly accurate to me or "in the ballpark" so to speak. Not sure how he came up with that graph. There are many variable and corals can and will adapt if carefully placed. Your better off to start low with anything if your not sure where it came froma nd what kind of lighting it was under.
Aquacultured corals do much better in tanks and are easier by far in my opinion to keep.

 

[dzhuo]

EDIT: found it. Is this still accurate? Table was not made by me, instead a far better RC user than me.

These numbers are base on a study by Dana Riddle and they look accurate. The study was published in 2004 and aim to provide guidelines of how much light corals receive in shallow water.

 

[Alex T.]

So, basically I'm wasting electricity running 400 watt Radiums in a 24 inch depth of water.:sad2:

 

[dzhuo]

Not necessary.

The study is aim to track photosynthesis efficiency and done so by using a Pulse Amplitude Modulation fluorometer (PAM-210). These numbers indicate where photosynthesis levels off (at photo saturation) and completely shuts down (at photoinhibition).

Photosynthesis is largely responsible for growth but lots of people aren't just concern about growth. They also want color which is a different story. However, there is a clear relationship between color and coral health. An unhealthy coral is not likely to show vivid coloration so at the minimum, providing more light beyond the photoinhibition point is useless because corals will start to show stress.

Also keep in mind that all corals Danna selected for this study come from very shallow water so you can imagine how much light corals in deeper water receive.

 

[Alex T.]

Not necessary.

The study is aim to track photosynthesis efficiency and done so by using a Pulse Amplitude Modulation fluorometer (PAM-210). These numbers indicate where photosynthesis levels off (at photo saturation) and completely shuts down (at photoinhibition).

Photosynthesis is largely responsible for growth but lots of people aren't just concern about growth. They also want color which is a different story. However, there is a clear relationship between color and coral health. An unhealthy coral is not likely to show vivid coloration so at the minimum, providing more light beyond the photoinhibition point is useless because corals will start to show stress.

Also keep in mind that all corals Danna selected for this study come from very shallow water so you can imagine how much light corals in deeper water receive.

All the more reason to go with the ATI Powermodule that I was thinking about getting. 400 watters just seem like overkill in 24" depth.

 

[Rockys_Pride]

These numbers are base on a study by Dana Riddle and they look accurate. The study was published in 2004 and aim to provide guidelines of how much light corals receive in shallow water.

Thank you.

 

[stpatrick]

Interesting.

 

[dzhuo]

All the more reason to go with the ATI Powermodule that I was thinking about getting. 400 watters just seem like overkill in 24" depth.

You really have to try and experience to see what works or doesn't. This part of the hobby - try, observe, change, try again, observe and compare - can't be easily skipped. Although the numbers can be used as base line reference point, it really goes beyond that since photoinhibition is not just a function of light; it's probably a combination of many different factors. Increased flow, for example, can significantly increase (sometimes double or triple) the photoinhibition point.

Jake Adams has done a study on P. damicornis in which he noted photoinhibition varies depends on flow. With flow at just 4.2 cm/s, the coral shows photoinhibition is less than 200 umol photons/m2/s. Increased flow to 10 cm/s, the coral will continue to perform photosynthetic until beyond 400 umol photons/m2/s.

Having said that, I do think most people over-do their lighting set ups. Most people are overly concern about lights and often try very hard to find the bluest highest PAR bulb for "pop" when other factors such as flow which is more important are often "ignored".

 

[rodneyri]

what do the 3 columns mean?

 

[dzhuo]

The first column is the compensation point and it means the minimum amount of light in order for the corals to survive or more correctly for photosynthetic to happen. The second column is the photosaturation point and it means beyond this level, more light wouldn't yield more photosynthetic. The last column is the photoinhibition point and it means the coral is starting to show signs of stress and shuts photosynthetic down to protect itself from lighting damage. Photoinhibition is a short term stress which most corals have envolved to deal with but if constantly being exposed to such condition, it will start to bleach.

 

[rodneyri]

cool thanks, so basically target 300-600 for acros