My tank PAR readings

[TurboGuru]

At the meeting last night I was given the opportunity to grab our clubs Apogee model QMSS-E quantum meter with separate sensor to take PAR readings of my tank.

I was able to place the sensor around the tank and for the most part readings were taken with the sensor facing straight up (some placements had a slight lean.) The measurements were taken with the flow still on to keep the chiller running and the ranges given are the highest and lowest displayed on the meter. Reading are PAR and expressed in microeinsteins per second per square meter. (umol/m2/s)


My tank (for those who don't know) is a 90g 4' standard with custom C2C overflow. The lighting is 2x250w MH (Aquaconnect 14k se) with batwing reflectors and 2x110w VHO (URI 454 and SuperActinic both 46.5") with only internal reflectors. Bulbs have approximately 4 months of use VHO= 11hrs/ day, MH=5hrs/day.

Tell me what you think.

[NONNA58]

I am not understanding the range you have on each location you measured.

[TurboGuru]

Originally Posted by NONNA58

I am not understanding the range you have on each location you measured.

Because I did not shut off the return pump (4800gph) the surface of the water was agitated. The meter jumped around, the number ranges given are the meters readings, highest and lowest.

[TurboGuru]

The reasoning for not shutting off the pump is that the water level drops about 1 inch and all equipment (chiller, reactors, etc....) feed from a manifold supplied from the main return line. In other words, the chiller would be off allowing the tanks temp to exceed parameters and the water level would be lower giving false high readings.

[NONNA58]

the top center is real low. Do you have the 2 bulbs reaching the center at all?

[TurboGuru]

Originally Posted by NONNA58

the top center is real low. Do you have the 2 bulbs reaching the center at all?

Right where the purple digi is (top center) is above the crossover of the reflectors output and right below the center brace. Hopefully the digi will grow slower there.

[NONNA58]

okay, so I have the same bulbs as you, but three and different reflectors. My tank is 27" deep. I have two 24" super actinic vho's that are 75w in the front and one 48" super actinic vho that is 110w. They both state the par reading peaks at ( blue spectrum) 420. Did you try the par meter for just the actinics?

I am curious to see what mine reads. I am not sure that par readings are good, so are yours good?

Come by some night and bring the meter and we can check out my tank.

[TurboGuru]

Originally Posted by NONNA58

okay, so I have the same bulbs as you, but three and different reflectors. My tank is 27" deep. I have two 24" super actinic vho's that are 75w in the front and one 48" super actinic vho that is 110w. They both state the par reading peaks at ( blue spectrum) 420. Did you try the par meter for just the actinics?

I am curious to see what mine reads. I am not sure that par readings are good, so are yours good?

Come by some night and bring the meter and we can check out my tank.

I did not do only VHO readings, I may before I bring the meter back. The meter does not show what spectrum the PAR peaks at. There is a spectral range that is used by photosynthesis, AFAIK the par readings from the meter encompass that entire range.

[puntific]

How much did your meter cost? My club is thinking about getting one... What brand?

puntific

[mdemuth]

Interesting readings

[bgdiving]

Your readings all look higher than the ones I got with that meter 2 days ago. I'll have to dig out my readings, wish I could put numbers on a photo like you did, would be much better than trying to describe where the readings were taken. Glad you posted your readings! Now we just have to figure out what the readings are telling us. I know I was surprised to find my tank with 400 watt halides with reflector was much dimmer than the tank with with T-5s wtth out reflectors. There were a lot of uncontrolled variable but both mesurements were taken at the brightest spot with the sensor resting on the top wrack. But that did explain why I was getting some bleaching of corals that were fragged out of the halide tank and placed in the T-5 tank, not what I expected but the light meter confirmed what the corals were trying to tell me.

It will be interesting to see what light ranges people are growing various corals under.

[TurboGuru]

Originally Posted by puntific

How much did your meter cost? My club is thinking about getting one... What brand?

puntific

Brand is stated in the original post. "Apogee model QMSS-E quantum meter with separate sensor" I do not know the cost. PM "NONNA58" for info, she is our club president.

Originally Posted by bgdiving

Your readings all look higher than the ones I got with that meter 2 days ago. I'll have to dig out my readings, wish I could put numbers on a photo like you did, would be much better than trying to describe where the readings were taken. Glad you posted your readings! Now we just have to figure out what the readings are telling us. I know I was surprised to find my tank with 400 watt halides with reflector was much dimmer than the tank with with T-5s wtth out reflectors. There were a lot of uncontrolled variable but both mesurements were taken at the brightest spot with the sensor resting on the top wrack. But that did explain why I was getting some bleaching of corals that were fragged out of the halide tank and placed in the T-5 tank, not what I expected but the light meter confirmed what the corals were trying to tell me.

It will be interesting to see what light ranges people are growing various corals under.

I have no idea why your readings are lower than mine, maybe because your 400 watters were so far above the tank and your T-5s don't have reflectors.

As far as what the readings tell us I did some reading on the web and found this article (see link below) although it does not relate to corals it does relate to photosynthetic plants and different ways that light output is expressed. I found the most informative part of the article to be towards the end.

http://fins.actwin.com/aquatic-plant.../msg00022.html

As for the bleaching it think it has to do with the height of your 400s vs. the height of your T-5s. If your T-5s had reflectors your PAR would be significantly higher IMO and the bleaching would have been far worse.

Hopefully some other people contribute to this thread with their numbers so we can compare.

[leftcoastreefer]

Are the aquaconnects SE or DE? Everyone I talk to about them, claims they are the highest of PAR values. The only light comparison I have ever read was sanjays, and it claims otherwise. I run a 250 phoenix on an electronic icecap. I know many people in the area run this setup and I would love to see the comparison. Also what ballast do you run, as this can be a determining factor.

[GlassReef]

Originally Posted by puntific

How much did your meter cost? ... What brand?

puntific

As already stated, above, the meter was made by Apogee. Unfortunately they no longer manufacture the QMSS-E. They have a new model, the MQ-100. Where the QMSS-E was calibrated for electronic (bulb) lighting only, the MQ-100 can be switched between sun and electronic calibrations. It also can store up to 99 data readings - something the older model could no do. They sell for around $300.

[GlassReef]

Originally Posted by bgdiving

Your readings all look higher than the ones I got with that meter 2 days ago. I'll have to dig out my readings, wish I could put numbers on a photo like you did, would be much better than trying to describe where the readings were taken. Glad you posted your readings! Now we just have to figure out what the readings are telling us. I know I was surprised to find my tank with 400 watt halides with reflector was much dimmer than the tank with with T-5s wtth out reflectors. There were a lot of uncontrolled variable but both mesurements were taken at the brightest spot with the sensor resting on the top wrack. But that did explain why I was getting some bleaching of corals that were fragged out of the halide tank and placed in the T-5 tank, not what I expected but the light meter confirmed what the corals were trying to tell me.

It will be interesting to see what light ranges people are growing various corals under.

I run 400W Reeflux bulbs in LumenBright reflectors. The bulbs are 16-1/2" from the water's surface.

My readings are in the:

low 800s just above the surface
650s just below the surface
low 400s in the mid regions
low 200s at the bottom

Those readings are what I would have expected, after referring to those done by others, such as Melev, etc. For those interested, check out his site: Melev's PAR Readings

If your readings were lower than TurboGuru's, then my guess is the readings you got of your 400W lights were either flawed, or the meter is damaged or needs calibration.

When taking readings with my Apogee meter, I found that the position of the probe is very important! A deviation of only 10deg from the vertical can cause large variations in the readings obtained. It almost requires that a stationary mount be used.

As to what PAR number are required, I've read scientific articles where the authors stated that 400 seems to be the optimum and any energy above 700 goes un-utilized.

---------------------------------------------------------------------------------------

All that said, I really don't think PAR readings should be seen as so important. If your tank has a "normal" water depth of 20" to 25" and you are running 250W or 400W bulbs - assuming your water clarity is good and your photo-period is sufficient - your corals are getting enough light.

[TurboGuru]

Originally Posted by GlassReef

If your readings were lower than TurboGuru's, then my guess is the readings you got of your 400W lights were either flawed, or the meter is damaged or needs calibration.

He used the exact same meter I did and I used it after him.

[TurboGuru]

Originally Posted by leftcoastreefer

Are the aquaconnects SE or DE? Everyone I talk to about them, claims they are the highest of PAR values. The only light comparison I have ever read was sanjays, and it claims otherwise. I run a 250 phoenix on an electronic icecap. I know many people in the area run this setup and I would love to see the comparison. Also what ballast do you run, as this can be a determining factor.

Mine are SE. I am currently using them on "batwing" style reflectors. As soon as I am able, I will be building a new taller canopy to accomodate my 2 DIY "Lambenmax Elites" 14"x14" reflectors and 3x110w VHO. I'm curious to see what changes that will make in the readings. I am also using older Icecap ballasts for the MH and an ARO440 for the VHOs.

[bgdiving]

TurboGuru, did you change any settings or just turn on the unit after I used it?? I'll try to get some pics tomorrow and post the readings for the areas pictured. I'm a little technologicaly challenged, I can grow corals easier and faster than I can take pics and post them.

[TurboGuru]

I just turned it on and used it. I figured it was factory calibrated and didn't want to mess with it.

[bgdiving]

I assumed you hadn't changed anything from the way I used it but just wanted to verify.

[TurboGuru]

I found another thread that shows PAR values overlaid on tanks for comparison purposes.

http://reefcentral.com/forums/showthread.php?t=1773012

Discuss.

[TurboGuru]

Pic of the current lighting setup that was measured (the moonlights are not there anymore.)