The minum PAR fos SPS
- Thread starter frank88
- Start date
I'm not an expert but I was reading my corals book the other day and it talked about corals and how they manage / adapt to strong light. It said corals spends their energy producing mucus to help cope with uv / strong sunlight.
It is possible that corals can deal with very strong lights but in expense of energy and probably takes time to acclimate to it. I also have my share of bleaching corals because I've placed them in high light area too quick (and I would believe my 250 watt MH lights are not putting out anything more than 600 PAR). It could be possible that from the time the corals got harvested, they were shipped in complete darkness and have little to no reserved energy in them for mucus production. And hence lots of bleaching happening when we put them in HIGH / HIGHER par area in our tank.
Now corals might have better color when they adapt to the strong light area but may be the trade off is growth (because the amount of energy / resources that is being use for uv protection). I have no proof or studies to back up this theory, just something that came to mind after reading the book last week.
Steven
It is possible that corals can deal with very strong lights but in expense of energy and probably takes time to acclimate to it. I also have my share of bleaching corals because I've placed them in high light area too quick (and I would believe my 250 watt MH lights are not putting out anything more than 600 PAR). It could be possible that from the time the corals got harvested, they were shipped in complete darkness and have little to no reserved energy in them for mucus production. And hence lots of bleaching happening when we put them in HIGH / HIGHER par area in our tank.
Now corals might have better color when they adapt to the strong light area but may be the trade off is growth (because the amount of energy / resources that is being use for uv protection). I have no proof or studies to back up this theory, just something that came to mind after reading the book last week.
Steven
MechEng99
aka Reef'd Up
I use the saturation/photo-inhibition points for my main display when placing corals. I find it to be a good starting point. My main display has PAR of about 500 on the sandbed in many places...and almost to 1000 at the top of the tank.
However, keeping well-colored SPS is possible in lower lit areas (as compared to the "500-600 minimum" as mentioned by Acrotrdco). Take my QT & my grow-out tank for examples. The corals pictured below were in each spot for about 6 months (plenty of time for coloration to appear/fade). I won't say the corals in the QT tank are well-colored, but they are healthy and doing well (Acroporas included).
I really don't recommend those 500-600 PAR levels as a "minimum". I've played around with some corals (Seriatopora & Montipora) outside their published photo-inhibition levels, and after a year of exposure, they still haven't grown...or adapted to the lighting (this wasn't a serious study...just wanted to see if I had similar results from a published paper). They're still alive, still put out polyps, but they're still mostly bleached.
QT Tank (~125 PAR)
Grow-out tank (~225 PAR)
However, keeping well-colored SPS is possible in lower lit areas (as compared to the "500-600 minimum" as mentioned by Acrotrdco). Take my QT & my grow-out tank for examples. The corals pictured below were in each spot for about 6 months (plenty of time for coloration to appear/fade). I won't say the corals in the QT tank are well-colored, but they are healthy and doing well (Acroporas included).
I really don't recommend those 500-600 PAR levels as a "minimum". I've played around with some corals (Seriatopora & Montipora) outside their published photo-inhibition levels, and after a year of exposure, they still haven't grown...or adapted to the lighting (this wasn't a serious study...just wanted to see if I had similar results from a published paper). They're still alive, still put out polyps, but they're still mostly bleached.
QT Tank (~125 PAR)
Grow-out tank (~225 PAR)
This chart is far more accurate, look at the low saturation points of the various corals.
So.... 10 for Sprung is 600-700 Par...max max....
Some PAR reading (1 year ago) Perth Australia (nowhere near 2200 that is suggested here) unshaded clear polycarbonate
1 year later shaded reduced 25% if not even shallow water acros (several guys I know are collectors) bleach out
is solar light? your tank is lit by sun?
shananagans
New member
Good info. I will be switching over from t5s to leds soon and I am hopeing that I will not bleach things out as they will be stronger. I want to turn more leds on over a few days to help acclimate them.
I currently have a 20" deep tank and run t5s and my sps frags on the sand do well. I actually notice better results down there with increased waterflow.
I currently have a 20" deep tank and run t5s and my sps frags on the sand do well. I actually notice better results down there with increased waterflow.
rhys123
New member
Yes for 9 months of the year my tank is 100% lit by the sun (roughly 9 hours per day) under clear polycarbonate (the 250W MH are in their storage position they take up the slack over winter on a light rail)
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2200 par for natural sunlight is a little to high (unless you guys are burning more candles when the sun is facing you)
in august...in Hawaii at noon maxim peak is 2200 par..test to measure at noon on a clear cloudless day and tell me
Photosynthetically Active Radiation (PAR) is the metric used here to describe sunlight intensity. PAR is usually reported in units called micromole photons per square meter per second (molm²sec). Maximum PAR at noon on a clear day here in Hawaii is ~2,200 molm²sec.
PAR was measured with a WatchDog™ data logger and a water-proofed PAR sensor manufactured by Spectrum Technologies, Inc., Plainfield, Illinois. In order to compare the total number of photons falling upon a given area, we can use the information gathered from the data logger and calculate the Daily Light Integer (DLI). Fortunately, the Spectrum Technologies' software is capable of generating this information in a report and relieves us of tedium involved with manually calculations.
http://www.advancedaquarist.com/2009/7/aafeature2
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rhys123
New member
Not a problem I will test PAR on Tuesday (our next clear day we have a cyclone coming in from Sunday) at 12 on a nice clear day for you (today was a nice clear day a little later then 12 but ......)
I have never seen PAR reading here (Perth) at or near 2000
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to be precise, not to challenge (because I do not trust you) just to compare the data of Dana Riddle.
you think there may be differences between Honanau (Hawaii) and Perth?
I think you ... Honaunau is much closer to the equator ...I think there are significant differences in climate ...I could be wrong of course
dixiedog
New member
rhys123
New member
True it is closer to the equator (Honaunau).
Perth Latitude is 31° 60'S - Longitude 115° 50' E and Hawaii latitude is 21º 18' N, 157º 51' W so we are about 10 ° more (but to the south) away from the equator (whether that would make that much of a difference or not who knows)
Climate Perth is definitely hotter, dryer then Hawaii looking at the weather information available on the internet (I having been to Hawaii several times)
Anyhow the next clear sunny day we have I will see if I can get a good par reading at 12 (maybe today maybe not).
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NVfishman
Premium Member
I have a tank with a ton of acros and sps. The minimun acros handle 100 par even lower for garf bonsi and a few deep water acros that have somthing shading them. plating montis and most encrusters are 100 par. Most of my acros do best at 200-300 par. i use 10ks to get more par and better growth
12 o'clock today
The sky 1 or 2 seconds after taking the next picture
Still below the 2200 mark (clear blue sky no clouds in front of the sun)
you are in Summer in Australia?
rhys123
New member
Right dead smack in the middle of summer (45"C days bite the proverbial big one)
Sun is just about dead smack right over the top of us now
Hello Frank and everybody else.
The more i read on this subject from experimental data and from practical expierence, the more i get convinced that coral photoadatation is fundamental. This is particularly clear when we read that with 400 PAR corals bleach... Nature, and the sea in particular, is quite different from the water we have among those 5 glasses... The water in our tanks is different in many ways and the combination of its parameters heavily affects our results. SPS need not only light, but also food and all the bricks to grow their skeleton. These three elements must be combined togheter to achieve the hoped results. In conclusion we can have good colours without great growing rates, but if we push coral to grow with much light, they need also calcium ad much food. An healthy growing coral willl be surely bright and colorful if the tank is well set up and can manage a good quantity of food. In my tank i haven't found yet the limit for the excess of food: i can put in what i want that inorganics won't increase. But if organic excesses corals consumption, they will get darker. Increasing light (also duration, and that's what i'm doing) they need more food, otherwise they get lighter and then bleach. More light, means more growth and they also need calcium (i keep it at 500 mg/l), but growing rate is very good and tissues are much more thick.
The more i read on this subject from experimental data and from practical expierence, the more i get convinced that coral photoadatation is fundamental. This is particularly clear when we read that with 400 PAR corals bleach... Nature, and the sea in particular, is quite different from the water we have among those 5 glasses... The water in our tanks is different in many ways and the combination of its parameters heavily affects our results. SPS need not only light, but also food and all the bricks to grow their skeleton. These three elements must be combined togheter to achieve the hoped results. In conclusion we can have good colours without great growing rates, but if we push coral to grow with much light, they need also calcium ad much food. An healthy growing coral willl be surely bright and colorful if the tank is well set up and can manage a good quantity of food. In my tank i haven't found yet the limit for the excess of food: i can put in what i want that inorganics won't increase. But if organic excesses corals consumption, they will get darker. Increasing light (also duration, and that's what i'm doing) they need more food, otherwise they get lighter and then bleach. More light, means more growth and they also need calcium (i keep it at 500 mg/l), but growing rate is very good and tissues are much more thick.
