Been frying my corals because of this!

[hockeyhead019]

Still so much to learn in this hobby lol. Great thread and thanks to everybody who chimed in about their PAR meters. *Furiously begins to search for PAR map for current light fixture*

 

[CindyKz]

Great thread! I don't have a PAR meter handy but I know from previous readings my PAR levels are much higher than Dana's recommendations. I've been seeing slow growth and poor colors - dialed my lights back a bit to see if it helps. Looking forward to following along.

 

[Dana Riddle]

Great thread. Thanks for sharing Dana's presentation.
Dana, how does the max saturation play into growth still in the p.m.? From descriptions on this before I'd think they would shut down until the next day versus firing up again in the p.m. after likely hitting max sat. This makes me think that a long photo period, at the peak PAR for max growth, would keep them growing.
Todd

The protective xanthophyll cycle reacts to light intensity. One of the goals in the experiments I did with Porites was to examine if these shallow tide pool corals had adapted somehow and could tolerate high light intensity. If so, how much light? As it turned out, the photosaturation point was reached in the early a.m. Although I did not look at the recovery in the afternoon, there is plenty of evidence (by others with different species) that photosynthesis rates are proportional to light intensity once it falls below the saturation point. I agree with your premise - maximum growth could be achieved if light intensity is at the saturation point and photoperiod is reasonable - 10 to 12 hours should do it. I'm not a big fan of 24 hour illumination.

 

[Mark Gray]

I voted yes but it's not really true yet cause I bought it for my new build, witch just got water in 2 days ago. So my Par meter is still in the box. so yes I have one no I have not used it yet

 

[Ferrell]

Here is the video I just saw yesterday for the first time thanks to @MJC

That is an awesome vid. Have watched many times

 

[JimP]

Neptune PMK.

 

[Brian W]

Yes I use the seneye pay meter. It will be interesting to see what my T5 levels are after 6 months, 1 year and 2 months use. Just to see how much and when their brightness actually diminishes

 

[Dana Riddle]

Thoughts on the light project. Use Halldal's action spectrum for zooxanthellate from a Favia, look at Jerlov's light attenuation coefficients for coastal and oceanic waters. Calculate PUR for various light sources. Write a program in Excel and crunch some numbers.

 

[Reefer Reboot]

Just some of my personal observations. I own both the Seneye Reef Monitor and the Apex PMK. I have mounted them right next to each other on an adjustable holder to compare real time readings simultaneously. Overall on average they agree with each other. But this is after they have sat in one position for a while to get an averaged out reading. They each have their own pros and cons. The Seneye gives quicker real time readings when using the app screen (SCA), less than one second time delay. Seneye uses a clear lens over the sensor which is great for quick readings. Thus it is also more affected by surface agitation, resulting in greater fluctuations of the real time readings. If it is left in the tank the results are also quicker to be affected by algae growth on the lens. The Seneye online Dashboard takes one reading every 30 minutes to chart out the trend. The PMK takes a reading every 5 minutes as displayed in Apex Fusion. The PMK uses a translucent white lens cover, thus not being affected by surface agitation as much. So with the lens cover and the more frequent readings the resulting trends comes across as smoother. Also the algae growth that occurs on a constantly submerged PMK sensor does not affect it as quickly, but will in the long run. (Side note, you can tell how often a snail cleans the lens from the slow drop in PAR to the sudden jump back to where the readings were before.)
So as far as Par goes, if you're looking for instantaneous readings my vote would go to Seneye. If you want more data points graphed out and averaged, I would vote PMK.
Now, after all that non conclusive mumbo jumbo, there is this to think about. If you run an Apex, using a PMK puts it all right there on the controller screen. If you run Seneye it will require additional software/website. (This may be a non issue.)
And in the spirit of being non biased, Seneye is more than just a PAR meter. It also includes Kelvin, Lux and a color spectrum graphs (As well as the ability to measure temp, PH, free ammonia, NH4, and disolved oxygen.)
And finally, (Sorry, don't mean to hijack, just want to be fair.) some of you may have seen my rants about Seneye's color graph spectrum not reading the red spectrum correctly. I was using it in my refugium (See in Senye's forum). While writing this, I plugged my Seneye back in to verify the reading frequency and have found that after their latest update, the color graph spectrum is now reading AND plotting the red spectrum correctly. Yippee, ;Happy;Woot, good on you Seneye! Guess I'll reincorporate it back into my setup. Other than that, great info here. Thanks!

 

[Dana Riddle]

Per the comments above, a quantum sensor constantly submerged will eventually develop light-absorbing/reflecting growths and will require cleaning.
Meters have a 'refresh rate' - some average light measurements over the course of a second or so. I purchased a quantum sensor years ago with a refresh rate that could actually see the 60 Hz off/on cycles of a metal halide lamp. Needless to say, it was useless for use with many artificial light sources since it was designed for use with sunlight.

 

[Reefer Reboot]

LOL, Yup, that's the problem with sensors. Without knowing the sampling rate they can really skew test results.

 

[Servillius]

This thread has me thinking of new experimental protocols. I think I can settle issues debated here. Into the lab I go.

Give us a hint? I’d be very excited to hear what you have in mind!

 

[TexasTodd]

Thanks Dana, that helps. I thought they totally shut down after max sat. I used to run a 10 hour period at max with halides but of course no PAR meter back then. But, did have very good growth.
Maybe this time around I'll run lower PAR for growth then work up higher for better color at some point. With the microfrags people sell these days we need growth at first!

 

[User1]

I don't use one so voted no. It is something I've considered in the past but the entry point with regards to quality and consistency vs. price and packaging hasn't been a easy pill to swallow. More so when you look at the other equally if not more important necessities. I'm using custom DIY multi-chip LED's with a rather high mix of green and blues so can see the value. So yes, it is a valuable tool in our box but I can't justify it yet sadly - at least in my case today.

The good news is I have a controller and can adjust has I see fit. Blessing and a curse I guess because it means I can fiddle too much and cause issues. So what I do is this. I know now in California the sun rises around 0540'ish up North - so my lights kick on at 0600. Sun sets around 2030'ish. So what I was doing with my Reef Angel controller is use the Parabola function to ramp up and down which then would give me a window to reach 100% briefly but then ramp up and down the rest of the day. Trying to replicate that a bit with the Apex I've since converted to without killing the tank

If I had a meter - looking at it that way I think I could fine tune spectrum - which would be ideal since I have two different chips I'm using (blending) - while reaching that afternoon intensity. I'm not sure if 200 dollars for a par meter (seneye) makes sense since I already have a controller. And the other meters are more expensive...so other pieces of equipment or supplies are a bit more higher priority although I do see the value if that makes sense.

 

[d2mini]

I would like to see some par numbers from different reefs at different depths.

Here's my PAR readings using the latest model apogee under my Radion Pros.
Lights are 17" off the water and the tank is 19" tall.
Yellow numbers are as close to center as possible, blue is bottom at front glass.

 

[biecacka]

Dana, in addition to wants to achieve those numbers is there anything said about the length of time we run our lights? What have you found to be "enough" as far as duration goes.
If we lower our par, do we increase our viewing period or is there no real correlation?

Corey

 

[bhuyett]

I will have to watch the video more in depth I flicked through it a bit. I don't want to come off as rude or disrespectful because this guy in the video is clearly well known. I don't follow many big names in reefing hell I only know Randy's name because ive always used Randy's recipe haha!

I have ran sps acros at near 700 par and they produced some of the best colours yet, corals thrive in varying light in the wild. most of the time in the last 10 years the talk on sps is high par 350-400 plus. I can respect his conclusions and scientific methodology to do this, but I come from medicine, and in medicine one study or one trial means not much. It needs to be proven repetitively to ring true. It's an interesting thought and outcome from his study though and worth looking into more, and reefers like yourself experimenting with the lesser par.

On the flow side of things i think we under value that a lot, I think that's definitely on the money from my experience both in a tank and in the wild.

To Luno's concern, actually Dana does bring up higher PAR and color. Around that 13:30 mark, he specifically says, "At the higher PAR levels you can get the color, but the coral growth rate is probably going to go down."
For me it isn't about the growth rate, because my Acro's grow fast enough. I lean more towards the color side.

 

[Dana Riddle]

Dana, in addition to wants to achieve those numbers is there anything said about the length of time we run our lights? What have you found to be "enough" as far as duration goes.
If we lower our par, do we increase our viewing period or is there no real correlation?

Corey

Yes, it's called the Daily Light Integral. See here for details:
https://www.advancedaquarist.com/2013/9/aafeature
I incorrectly called the DLI 'Daily Light Integer' in this article. In any case, it provides the formula to calculate the total dosage of light in your aquarium (assuming you have a PAR meter.)

 

[Centerline]

Here is the video I just saw yesterday for the first time thanks to @MJC

Great video!

 

[Centerline]

Finally got a Neptune System PMK (par meter) and was able to test it against my 10+ year apogee par meter and the PMK is testing about 80 par higher than my old meter. Which really explains a lot of confusing coral deaths. I love the long wire on the PMK and that I can place it anywhere and just eye the reading on the controller display, ipad or phone. I know this sounds a bit like a commercial but it's not, I'm just really happy with it so far and super happy to have some better data on par levels in the tank!

• So with all that said I am wondering how many of you use a PAR meter of some sort and what brand do you use?

• Have you ever found discrepancies between par meters?

I have a PMK , Seneye and a SQ-520 that I have yet to use. I really like the PMK because that rock makes a nice stable platform. Correcting for the blue light is easy enough and all in all its a great product.