What's Your Lowest Successful PAR Level?

[Dana Riddle]

So I have a reefbreeders Photon 48. I love the 20k look but have been told that my par of like 165 on the rocks with the light at that setting (100 blue, 5 white) is too weak for sps.

So in reading this that is quite possibly wrong?

In many cases, yes, SPS corals can survive in amazingly little light although spectrum undoubtedly plays a part, as does feeding. Many - not all - Pacific SPS corals (Acroporas, Montiporas, etc.) contain Clade C zooxanthellate and are less tolerant of high light than, say, Clade A zoox. But these myths about SPS requiring high light intensity (define this vague term, please) go back decades and simply isn't true. I can provide hard data if you're not already familiar with it.

 

[Fritzhamer]

Great thread idea!

I remember Anthony Calfo in a speech years ago stating that the most colorful corals were usually picked from deeper water. There was an analogy to the leaves turning color if I remember correctly.

 

[Mindi]

Question....Is a LUX meter the same as a PAR meter..?

 

[BradB]

In many cases, yes, SPS corals can survive in amazingly little light although spectrum undoubtedly plays a part, as does feeding. Many - not all - Pacific SPS corals (Acroporas, Montiporas, etc.) contain Clade C zooxanthellate and are less tolerant of high light than, say, Clade A zoox. But these myths about SPS requiring high light intensity (define this vague term, please) go back decades and simply isn't true. I can provide hard data if you're not already familiar with it.

It was true decades ago, when 100 par was a lot of light. Now I can easily fry anything with a poorly placed $10 DIY Led array (drivers not included), but we didn't have those. The rule used to be no lights needed for fish only, high wattage VHO or MH for Acropora and anything in between for mixed other corals. I know there are other high light corals and low light Acros, but they were uncommon. I know Dana and Anthony know this because they were around, but other readers might not.

 

[AllSignsPointToFish]

Question....Is a LUX meter the same as a PAR meter..?

No, not exactly. The lux meter just measures light flux, but the PAR meter measures the amount of light in the right photosynthetic wavelengths.

 

[Dana Riddle]

No, not exactly. The lux meter just measures light flux, but the PAR meter measures the amount of light in the right photosynthetic wavelengths.

Good! To strengthen the definitions a little, lux measurements are weighted towards those wavelengths to which a normal human eye is most sensitive, that is, green wavelengths. The spectral response of a lux sensor is a bell curve peaking in the green area of the spectrum. PAR meters, on the other hand, report equally those wavelengths between 400 (violet) and 700 (red) nanometers. PAR measurements don't report all wavelengths used in photosynthesis but it is the standard used. Lux to PAR conversion factors are available for many 'aquarium' lamps.

 

[jda]

Can we please specify which PAR meter was used and which sensor, along with the light type? Not all of them are really that good at capturing, blue, purple and UV and a reading from an Apogee 510 will be different than an older model. There is probably somebody who is smart who can figure out a quick conversion between the different brands based on their reading curve. My Apogee 510 is sometimes nearly 60% higher than a reading from a 200 that my friend has.

 

[imustbenuts]

Well for the longest time I didn't have access to a Par meter. I have my two Kessil A360WE's over my 40 breeder, and I was scared as hell to burn or bleach my corals. So I never turned the intensity up past 30% When I finally did get a par meter, I found out that nowhere in the tank went over 80 Par. Yet I had SPS corals that were growing (very slowly, but they were growing) Jedi Mind Trick Monti, Reverse Superman Monti, Red Cap monti, Sunset monti, Tri color acro, and strawberry shortcake acro. Since then cranked it up to almost 70% and getting around 250-300 par at my SPS and everything is taking off and growing faster than I ever could have imagined.

How do you get 250 350 PAR from an A360we?

 

[Dana Riddle]

Can we please specify which PAR meter was used and which sensor, along with the light type? Not all of them are really that good at capturing, blue, purple and UV and a reading from an Apogee 510 will be different than an older model. There is probably somebody who is smart who can figure out a quick conversion between the different brands based on their reading curve. My Apogee 510 is sometimes nearly 60% higher than a reading from a 200 that my friend has.

Excellent point. If not corrected for the immersion factor, Apogee meter readings can be low compared to a LiCor meter (that has a correction toggle.) The newest Apogees are designed to deliver corrected measurements. See here for details:
http://www.advancedaquarist.com/2016/12/aafeature

 

[Big E]

This thread will probably get off track quickly, but how did the coloration respond (intensify/weaken)? I'm seeing good coloration and growth at a PAR of around 25 (mostly blue LEDs.) This is pretty darn close to the minimum needed by corals (the compensation point) but it's working for even corals that are generally considered (falsely) 'light-loving.'

Hi Dana,

What Sps species are you testing and what is the known coloration you're targeting? It would be nice to get more specifics on this. To be factual, one can only say that the specific Sps that is being tested can do well under only blue lighting and 25.

As an aside, I think it's time for Acropora, Montis, Seriotopa, Poccis, Stylos to all be in separate categories and needs instead of the general moniker of Sps. Even within species like Acropora there is a wide margin of intensity needs. I know in my system there are specific acro species that won't thrive at certain par levels, while others are more forgiving.

The statement " good coloration/growth" seems subjective and we all abuse this phrase. For example a guy that likes pastel colors definition is different than someone that wants deeper coloration.

 

[Dana Riddle]

These statements are based on observations made in multiple tanks, including my own. Let me find and unpack my 'good' camera and I'll get some photos posted as well as PAR info. Genera observed are Acropora, Pocillopora, Montipora, Acanthastrea, Echinophyllia, Pavona, Favia/Montastrea, Leptoseris, Euphyllia, Goniopora, Rhodactis/Discosoma, various zoanthids, and so on. Can't speak to color, but it appeals to me.

 

[Crabs McJones]

How do you get 250 350 PAR from an A360we?

I run them at 70% 6.5 inches off the waters surface

 

[Big E]

These statements are based on observations made in multiple tanks, including my own. Let me find and unpack my 'good' camera and I'll get some photos posted as well as PAR info. Genera observed are Acropora, Pocillopora, Montipora, Acanthastrea, Echinophyllia, Pavona, Favia/Montastrea, Leptoseris, Euphyllia, Goniopora, Rhodactis/Discosoma, various zoanthids, and so on. Can't speak to color, but it appeals to me.

Hmm.......25??? Is this a typo on your post #3. Maybe that's why I see such a disconnect. Did you mean 250?

That would match more to my experiences of a range of 200-450

From your article, again more in line with what I have seen.

 

[jda]

The lowest that I like to keep Loripes, Echinata, Granulosa, Lokani and the other deepwaters is 150 PAR on an Apogee 510 with 14K phoenix and 20K radiums. They will grow just fine, but the colors get darker, up to 350-400 - this can make CITR Red Dragon look better when darker and more red, but the grannies and lopries loose a lot of contrast with more light. Beyond this seems to be a waste with no extra growth or color. They can survive and not-do-much at 100, or so.

The lowest that I can grow tenius, pearlberry (whatever it is), micro, aculeus, torts (real and false) at 250 for good color and growth and can do well up to 500-550. Beyond has OUTSTANDING growth, but the colors fade. Again, on Apogee 510 with 14K Phoenix and 20K Radiums. These can survive and not do much at about 150, or so.

I cannot remember if you asked about softies, but I only keep OG WWC Bounces and Jawbreakers - both in my frag tank about 4" underwater under a 20K Radium on M80 at about 550 PAR on Apogee 510 and they can grow from a quarter to 2" in about 8-9 months. It has always been my experience that I cannot give these particular mushrooms too much light from a MH.

Lastly, I keep NSW Parameters - N clear on Salifert and P .01 on Hannah Ultra Low and I do not feed my corals other than fish poop.

 

[SciGuy2]

Time to dust off the VHOs and the IceCap ballast? I still love those Actinic 03's.

 

[Scott.h]

Quite honestly im surprised by some of the high numbers people run. My nutrients are always deteable 1/.010-ish, but my par numbers are in the 150 range, peak. My t5 fixture (1 purple, 1 Attinic, 1 coral plus, 1 aqua blue special, 4 blue plus) is the same size as my display, so my spread is ideal. Every time I try to up my percentage just 3% my corals pale quite fast. I've tried several times. I don't understand it but I've had to go with it.

 

[S-t-r-e-t-c-h]

Time to dust off the VHOs and the IceCap ballast? I still love those Actinic 03's.

For sure...

My first reef tank was a 55 gallon that had two 40w standard florescent bulbs. Just kept mushrooms and zooanthids, mostly, but leathers and montis did well in the tank. I even had porites pop up randomly as a LR hitchhiker (this was back when live rock came out of the ocean).

It lived like that for years before I upgraded to VHOs, which did open up my options a bunch.

 

[Dana Riddle]

No typo. PAR value of 25. And I should clarify - coloration means fluorescent proteins, not non-fluorescent chromoproteins (which seem, for the most part, to be induced by 'strong' lighting.) This PAR value is likely on the ragged edge of enough photosynthesis to meet the oxygen demand of the coral and symbiont - the compensation point. The impact of feeding/nutrient concentrations needs investigation, although I recall Julian Sprung seeing Acropora specimens being maintained under standard 40-watt lamps (no details, and much to his surprise) - he suspect heterotrophy supplemented phototrophy.

 

[Scott.h]

In many cases, yes, SPS corals can survive in amazingly little light although spectrum undoubtedly plays a part, as does feeding. Many - not all - Pacific SPS corals (Acroporas, Montiporas, etc.) contain Clade C zooxanthellate and are less tolerant of high light than, say, Clade A zoox. But these myths about SPS requiring high light intensity (define this vague term, please) go back decades and simply isn't true. I can provide hard data if you're not already familiar with it.

Given the generic term of sps, but referring to those, how can we tell which species require more light having the clade A? Is it solely trial and error?

 

[jda]

I see where you are coming from now. I am doing a similar experiment. I have two frags under a single ATI Blue Plus T5 on AquaMedic that are slowly dying. The bottom one is an unrecognizable Pearlberry and the one on top is a green/pink/white microlaudus encrusted nub similar to most Shortcakes. Both are now different colors of brown - red-brown and green-brown. After about two months, each are dying around the bases and from the tips. This tank is on the same system as my other acropora which are thriving. PAR from a Apogee 510 bounces between 48 and 53 and the bulb is directly above the frags.

Edit - amazingly, the coralline is growing quite nicely under this single bulb. Little dots pop up every week or ten days after I scrape them.