PAR Study/Experiment

[cpllongjk]

Problem: My display tank’s corals look amazing compared to the washed-out (pale) look of my frag tank’s corals.

Hypothesis: I am assuming water quality is not the issue since both tanks are connected. I am also assuming flow is not the issue since both tanks receive adequate random flow. The PAR over the frag tank has been adjusted to be similar to my display on the high to mid sections (roughly 350-200 PAR respectively). I believe that overall daily PAR intake of the corals is the culprit.

Experiment: I will measure the average PAR among 6 corals in my tank from 5am until 8pm in 1 hour intervals. Two corals from each major zone will be measured; two high, two mid, and two low. The goal is to know the “peak” PAR for the day as well as the daily PAR consumption of the corals in my display. Once this part of the experiment is completed I will measure and adjust the frag tank lighting to be more in line with the display in terms of overall daily PAR levels and wait to see what happens to frags of the same corals.

Equipment Used: Apogee MQ-500

The pictures below represent the 11 points of changes in lighting within the display tank.

Figure 1 0500 Royal Blues 0%, (Royal Blues begin ramping to 50%)


Figure 2 0900 Royal Blues 50%, (Whites and Blues begin Ramping to 5%)


Figure 3 0930 Royal Blues 50%, Whites and Blues 5%, (all LEDs begin ramping to 100% (RB 100%, W&B 10%))


Figure 4 10:00 All 4 T5s ON: (2) Blue+, (2) Coral+; All at 100%, No Ramping


Figure 5 1100 Royal Blues 100%, Whites and Blues, (Whites and Blues begin ramping to 30%)


Figure 6 1200-1600 Royal Blues 100%, Whites and Blues 30%, (1600 Whites and Blues Ramp Down to 10%)


Figure 7 1700 Royal Blues 100%, Whites and Blues 10%, (all LEDs begin ramping down to 50% (RB 50%, W&B 5%))


Figure 8 1800 All T5s OFF (All LEDs still ramping down)


Figure 9 1830 Royal Blues 50%, Whites and Blues 5%, (White and Blue ramping OFF (RB 50%, W&B 0%))


Figure 10 1900 Royal Blues 50%, Whites and Blues OFF, (Royal Blues begin ramping down to 5% (RB 50%, W&B 0%))

[cpllongjk]

Figure 11 2000 Royal Blues 5%, (Royal Blues ramp down all night slowly)



MORE COMING SOON AFTER I COLLECT SOME DATA!

I appreciate any criticism or questions you may have.

[bif24701]

Please give details on the fixtures about your display and frag tank. Also include mounting height from the water, bulbs, stuff like that.


Sent from my iPhone using Tapatalk

[cpllongjk]

Originally Posted by bif24701

Please give details on the fixtures about your display and frag tank. Also include mounting height from the water, bulbs, stuff like that.


Sent from my iPhone using Tapatalk

Will do! Sorry, its been a long time since I've done any type of research.

Display Tank
Dimensions: 24x20x20
Lighting: 24" ATI Hybrid 4 bulb (2 ati blue+, 2 ati coral+)
Mounting Height: 8" above waterline
Flow: return + 2 mp10wqd placed on back wall varied flow throughout the day

Frag Tank
Dimensions: 30x20x8
Lighting: 24" ATI Sunpower 6 bulb (3 ati blue+, 2 ati coral+) + 2 Reefbrite Tech All Blues
Mounting Height: 13" above waterline
Flow: return + 1 gyre 150 with flow on pulse mode at roughly 40-50% power

[2smokes]

PAR doesnt help you with nothing in obtaining better coloration of the corals from the light.A blue T5 has same ammount of PAR with a white T5.A par meter measures just blue and red colors from the whoole spectrum.If you have a bulb with a lot of red in it ,it will show you a good PAR value but corals will look bad.You want to have more blue than red so that the corals will look more fluorescent.If you want a super tool in measuring the spectrum them you could build a simple spectrometer from am old camera and a difracting grating made from a compact disc.With that you will know exactly how much red or blue there is in a bulb output(it measures the otther colors as well like green yellow etc).For the spectrometer you can check my forum thread here.http://reefcentral.com/forums/showthread.php?t=2606060

[cpllongjk]

Originally Posted by 2smokes

PAR doesnt help you with nothing in obtaining better coloration of the corals from the light.A blue T5 has same ammount of PAR with a white T5.A par meter measures just blue and red colors from the whoole spectrum.If you have a bulb with a lot of red in it ,it will show you a good PAR value but corals will look bad.You want to have more blue than red so that the corals will look more fluorescent.If you want a super tool in measuring the spectrum them you could build a simple spectrometer from am old camera and a difracting grating made from a compact disc.With that you will know exactly how much red or blue there is in a bulb output(it measures the otther colors as well like green yellow etc).For the spectrometer you can check my forum thread here.http://reefcentral.com/forums/showthread.php?t=2606060

The reason for this research is not to argue the aesthetic qualities of the different colored bulbs but to see if overall daily PAR intake of the corals matters.

The lighting over both tanks is close to the same but the frag tank's corals seem to be bleaching (pale in color and reduced growth).

There are two ways to fix this issue; (1) raise the lights over the frag tank or (2) decrease the photo-period. However, I am attempting to quantify the amount of PAR needed for the corals to look amazing and grow like weeds in my display and then replicate that in my frag tank.

[2smokes]

I toght your corals look pale in the frag tank because of the light spectrum.If they dont just look pale and they are trully bleaching then it might be from too much light intensity.For this you could dim the light or shorten the light period .Thoose T5 are good lighs with good spectrum and you cant go wrong with them except when the light is too intense for a too shallow water column in wich case a par meter is good to use.

[cpllongjk]

Originally Posted by 2smokes

I toght your corals look pale in the frag tank because of the light spectrum.If they dont just look pale and they are trully bleaching then it might be from too much light intensity.For this you could dim the light or shorten the light period .Thoose T5 are good lighs with good spectrum and you cant go wrong with them except when the light is too intense for a too shallow water column in wich case a par meter is good to use.

That is what I thought too... I cannot dim the fixture over the frag tank, it is either on or off.

I started by measuring the frag tank's par and it ranged from 200-350 PAR which is the exact same as my display tank's middle to high sections. I was perplexed because both tanks are receiving 8 hours of t5s at 100% however, the display only receives 4 hours of peak par (where the t5s are at full and LEDs are at 30% intensity). The other 4 hours that the t5s are on the LEDs are either ramping up or down. The LEDs in the hybrid only achieve a maximum output of roughly 30% for a 4 hour period.

[2smokes]

If you can not dim the lights in the frag tank ,maybe you could take the reflectors of the T5 tubes out.Without reflectors they loose somme intensity but best option would be to put dimable ballasts on the frag lamp;that way the T5 tubes will also last longer and they will draw less current.