Light Intensity in Successful Reef Tanks

GaryE · Apr 3, 2020

Question about par levels.

If I have two lights of equal par (per the manufacture specs), will the effective par at a particular level be double the level of just one of those lights or is there more math to consider?

jacobreynolds6883 · Apr 3, 2020

Big E said:
This is something that I don't understand.............why people are running LEDs that way?.........it's in deterence to what the corals need.

It's much simpler to run them the same as traditonal lighting. One of the biggest mistakes these LED manufacturers made was to offer all these options and make the software so complex and unnecessary.

It's the same as giving a 20 handicap golfer the option to change weight and launch angles on a driver.

So for corals it would be best to set the most optimal level to run throughout the whole light, how about fish and inverts? Does the mimicking of dawn to dust offer anything for them that is scientifically proven?

Dana Riddle · Apr 3, 2020

GaryE said:
Question about par levels.

If I have two lights of equal par (per the manufacture specs), will the effective par at a particular level be double the level of just one of those lights or is there more math to consider?

It depends a lot on the beam angle of the light plus many other things I'll think of after my second cup of coffee.

GaryE · Apr 3, 2020

Dana Riddle said:
It depends a lot on the beam angle of the light plus many other things I'll think of after my second cup of coffee.

Thats what I thought. I guess the only true measure is a par meter. $$$

Dana Riddle · Apr 3, 2020

GaryE said:
Thats what I thought. I guess the only true measure is a par meter. $$$

I consider a PAR meter to be an investment, especially when some coral frags cost hundreds of dollars. I am amused (sort of) when I hear of hobbyists obsessing over calcium or nitrate concentrations, but have no idea about light intensity.

Phildago · Apr 3, 2020

90's reefer said:
I was interested by the coralline algae levels of growth to lower light.
Coralline and coral growth in my tank is good at 9 months now.
4c+4b+ 4" off the surface. High levels of light have given excecptional coralline growth.

What's your par on the bottom. Since I turned my light up my coral line has been decimated

GaryE · Apr 3, 2020

Dana Riddle said:
I consider a PAR meter to be an investment, especially when some coral frags cost hundreds of dollars. I am amused (sort of) when I hear of hobbyists obsessing over calcium or nitrate concentrations, but have no idea about light intensity.

I suppose at the very least I'll need to rent one for a couple of days to see what's going on in there..

I'm one of those LED guys who has everything setup on a diurnal schedule. I don't have any significant corals in the tank as of yet, but I do have a nice BTA that's responding very well and a cluster of Zoa's that are growing. They were hitch hikers on a rock I got from a place in Ohio..

Big E · Apr 4, 2020

Dana Riddle said:
The only advantages I see with programmable LED luminaires are showcasing coral fluorescence and mimicking dawn/dusk that is apparently important in inducing spawnings in some fish species. But lights with programs for storms/lightning... give me a break.

Yes, on the fish acclimating for dawn/dusk, I agree. Some fish can get skittish, going from full darkness in the morning, but that is only on rare occasions, for example in a basement with no windows. Even then fish and corals have internal clocks that adjust. When my tanks were in dark basements, they would bed down before the lights would go out and corals would start to expand polyps as well.

Usually ambient light from windows is enough for dawn/dusk. I could see anthias and wrasses do spawning dances with all my lights off with only exterior lighting.

Showcasing corals--
I grew up when black light posters, lava lamps, ect. were popular in the seventies with younger people(usually on something

) I hated the look back then because it was tacky. If I wanted to see it for amusement I could go into the back part of Spencer Gifts for a few minutes(that was about all I could take). Who could forget Elvis posters and the guy smoking the joint. It's the same way I view these Windex tanks now................ewww!;Spitoutdummy

Lasse · Apr 4, 2020

GaryE said:
Question about par levels.

If I have two lights of equal par (per the manufacture specs), will the effective par at a particular level be double the level of just one of those lights or is there more math to consider?

Dana Riddle said:
It depends a lot on the beam angle of the light plus many other things I'll think of after my second cup of coffee.

Measurements we have done indicate that it is nearly exactly whats happens if the sources is close to each other. PAR is defined as photons per area and time. If you have a spot there fixture 1 gives X PAR and fixture 2 gives Y PAR in a certain spot - the resulting PAR is X+Y in just that spot. This means that the real PAR in a certain spot can be both lower and higher than doubling. It was also a tendency that X+Y was not always just X+Y. In some measurements - we get the result X+Y + z. Why - we could not say. It could be a fault measurement but the frequency of such measurements was a little too large to just dismiss it as error measurement. It could be a higher reflection in sand, rocks and windows too.

If you look at the whole picture in a tank with X volume and Y surface - you will double the total amount of photons per area and time for all levels in the tank if you double equal fixtures (as average) IMO

Sincerely Lasse

GaryE · Apr 4, 2020

Lasse said:
Measurements we have done indicate that it is nearly exactly whats happens if the sources is close to each other. PAR is defined as photons per area and time. If you have a spot there fixture 1 gives X PAR and fixture 2 gives Y PAR in a certain spot - the resulting PAR is X+Y in just that spot. This means that the real PAR in a certain spot can be both lower and higher than doubling. It was also a tendency that X+Y was not always just X+Y. In some measurements - we get the result X+Y + z. Why - we could not say. It could be a fault measurement but the frequency of such measurements was a little too large to just dismiss it as error measurement. It could be a higher reflection in sand, rocks and windows too.

If you look at the whole picture in a tank with X volume and Y surface - you will double the total amount of photons per area and time for all levels in the tank if you double equal fixtures (as average) IMO

Sincerely Lasse

Interesting. Thanks for the information.

Paul B · Apr 4, 2020

Belgian Anthias said:
How to define " a succesful reef tank"? In the 90's? In 2020?

I don't think you could define a Reef Tank as one entity. You have basically fish and corals.
I believe success is of those things live as long as their perceived natural lifespan.

With fish that is easy and if even one person can keep a Royal Gramma for 15 years, we know that that species can live at "least" that long. I think the oldest person was like 117 or something like that but we know we can't live longer.

So if for instance we keep a Royal Gramma for five years, that is a dismal failure

(I do not know the life span of a Royal Gramma, I just picked that as an example)

Corals are different because they don't have a lifespan and should live forever as most of them keep reproducing and growing on top of their parents.
Corals are the oldest organisms on Earth as far as I know. (not counting Betty White, who I love)

I think I have achieved success with fish as my fish almost all die of old age, but I failed miserably with corals. Most of my corals are less then 10 years old but my tank is a lot older.
Especially LPS which I can get to grow very large, then in a number of years they shrink which is not a success at all.

Sunny Goold · Apr 19, 2020

jreynolds6883 said:
Not trying to hijack your forum but I figured many of you could help with a lighting decision I'm facing. I'm currently cycling a 90g tank that I plan to move my 36 over to. At this point I've yet to purchase a light for this tank because of uncertainty and not wanting to buy something I may need to replace later down the road. So after tons of reading I've picked two different lights, however I'm struggling with choosing between the two. I need input on the choice, for now I only have softies but hope in time to have a wide range of corals except for the rare/extremely hard to grow. Currently only have $400 to spend but would like LED at some point either by hybrid option or full LED. Which would you choose?

1st choice - (2) Ocean Revive T247-B

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2nd choice - Aquaticlife G2 T5HO Hybrid LED, (As money allows add 2 AI Primes)

48" G2 T5HO Hybrid LED T5 Mounting System BLACK w/End Caps - Aquatic Life

Shop The Best Saltwater Aquarium Equipment & Supplies at Saltwater Aquarium. We Carry Everything you will Need for your Fish Tank.

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Someone suggested the T5s - I think that is a good move if your tank is 24" wide (front to back). But I would also consider Reefi - particularly if you want SPS eventually in the middle and LPS on both ends - from what I have been reading about those lights from serious SPS heads. It would allow more flexibility should you buy another light in a couple of years if you need more or if you upgrade your tank and @danlu_gt would help you dial them in for the coral you want to keep.

madweazl · Apr 19, 2020

Tim Olson said:
Great article! I don't know if this the right place to ask, but I've struggled with whether I have my A360X at the right intensity. So I'm wondering how the A360X intensity compares to actinic fluorescent lamps and/or T5's, using whatever measurement you think is appropriate. For example I currently run my A360X at 33% intensity, is that comparable to 4 T5's? Am I even in the ballpark?

This thread has some PAR data that you can use to get an idea between T5s and the Kessils (the WEs actually produce a little more PAR than the X at the cost of reduced spread).

Jase4224 · Apr 20, 2020

Paul B said:
I don't think you could define a Reef Tank as one entity. You have basically fish and corals.
I believe success is of those things live as long as their perceived natural lifespan.

With fish that is easy and if even one person can keep a Royal Gramma for 15 years, we know that that species can live at "least" that long. I think the oldest person was like 117 or something like that but we know we can't live longer.

So if for instance we keep a Royal Gramma for five years, that is a dismal failure

(I do not know the life span of a Royal Gramma, I just picked that as an example)

Corals are different because they don't have a lifespan and should live forever as most of them keep reproducing and growing on top of their parents.
Corals are the oldest organisms on Earth as far as I know. (not counting Betty White, who I love)

I think I have achieved success with fish as my fish almost all die of old age, but I failed miserably with corals. Most of my corals are less then 10 years old but my tank is a lot older.
Especially LPS which I can get to grow very large, then in a number of years they shrink which is not a success at all.

Your might appreciate this website, speaking of old..

STROMATOLITES - WORLDS OLDEST LIFE FORMS | Western Australia | www.wanowandthen.com

Stromatolites - World's oldest life forms | Western Australia

www.wanowandthen.com

SuperDodge · Apr 22, 2020

I wasn't reefing in the late 90's when this article was written but I was reefing in the early 2000's. I had more success with SPS under Metal Halide lighting than I've ever had under LEDs. Now - I don't have the latest greatest LEDs, so maybe that has changed.

With all that said, I still prefer LED lighting because I no longer have to run an expensive chiller to take out the heat put into the water by my expensive lights. I also no longer have to put cooling fans everywhere and then replace them all the time because of salt creep issues. I think LED lights are the right answer, but I think they are more fidgety that MH was. As an idiot new reefer I was able to put MH bulbs in a reflector with a digital timer and have great success.

SuperDodge · Apr 22, 2020

Sorry - got a server error then a double post.

MnFish1 · Apr 25, 2020

Dana Riddle said:
The only advantages I see with programmable LED luminaires are showcasing coral fluorescence and mimicking dawn/dusk that is apparently important in inducing spawnings in some fish species. But lights with programs for storms/lightning... give me a break.

I agree - but - how does the sun work on the reef. Does it 'click on' at 6AM - and shut off at 6PM? no - so though I dont believe (like you said) in all the settings - but - that said - its weird that for some reason people think just an on/off is as good as 'nature'.

Also - I cant Read the article - at all maybe its my browser.

User · May 6, 2020

MnFish1 said:
I agree - but - how does the sun work on the reef. Does it 'click on' at 6AM - and shut off at 6PM? no - so though I dont believe (like you said) in all the settings - but - that said - its weird that for some reason people think just an on/off is as good as 'nature'.

Also - I cant Read the article - at all maybe its my browser.

Totally agree- dawn/dusk ramping and +/- moonlights since thats how light in nature works. Ive actially lost two very skittish fish due to them being startled when the lights suddenly switched on, despite ambient levels in a room where an entire wall is south facing windows

No to the special effects though.