Have we been wrong in our understanding of PAR this whole time??

[Troylee]

Didn’t have the radium’s but loved my pheonix 14k

Very similar! I have both to this day and I run the Phoenix 14k myself.. a radium on a m80 ballast looks better visually thou! I think the numbers might be slightly better… both bulbs side by side on a hqi ballast you can’t tell the difference really.

 

[HudsonReefer2.0]

Wasn't a challenge to you but rather asking for clarity. Working for you may, or may not, work for me. Or any hobbyist for that matter. Thus me tripping up over the "proven" choice of wording.

• Is it the type of light?
• Is it the spectrum?
• Is it the duration?
• Is it your experience?
• Is it luck?

So many variables.

I have grumpy old man moments, and yes to all but luck.

 

[HudsonReefer2.0]

Very similar! I have both to this day and I run the Phoenix 14k myself.. a radium on a m80 ballast looks better visually thou! I think the numbers might be slightly better… both bulbs side by side on a hqi ballast you can’t tell the difference really.

And the ab 10k where crazy white full blast and things were just real under them

 

[Troylee]

And the ab 10k where crazy white full blast and things were just real under them

I was always a xm guy myself but those non existent for many years now.

 

[HudsonReefer2.0]

And the ab 10k where crazy white full blast and things were just real under them

Wish I had some old halide lamp burn ins pics for a side by side comparison from the old old old tank lol. Not for par measurements but just for us from what we see

 

[MnFish1]

It could just be the look the hobbyist wanted at the time. Who knows. Personally speaking I preferred my dual 175W PFO ballast with urisho bulbs and a pair of 48" svho actinics.

Just as an aside most hobbyist are not trying to grow corals at the rate of a small business aquaculture facility. Again we are hit with marketing and social media with the potential side hustle but at the end of the day true hobbyist prefer growing larger colonies and maturity over time. Not I can clip 1/4", glue, wait a day, and sell for $150.00.

Just my opinion but then again maybe all the true hobbyist have left...

I know - since I heard the arguments lol

 

[jda]

Yep - these were magic.

My general advice is not to believe anybody who tells anybody that X or Y can do what Z did. No chart, graph, light meter reading, or anything can show you what things can do. The only people who say such things have never experienced them. Anybody who shows you a chart alone without any nuance from personal use probably is selling you short, IMO. If I had a dollar for every clown who tells me that XYZ can do the same thing as a VHO Super Actinic by looking at a chart, I would have a small fortune, or enough to take a vacation, at least.

On good reflectors, it takes 2x T5s to equal a single T12 VHO - it is just hard to get good reflectors for T12 anymore, or ever really. T12s last almost twice as long and you replace half of them. In the end, T5 just had a better public relations firm.

 

[jda]

I just wonder why there is such a debate about this topic

In general, I think that the people who do not understand the debate or discussion usually do not have the experience or ability for nuanced thought to be on the same level as people who have both. The ones who lack tend to go towards non-useful phrases like "they all grow coral" like somehow that matters... all cars can get you to a destination, McDonalds or a balanced diet can keep you alive, etc. Most of the conversation is about the nuance, the over generalization, some details that people do not know, etc. They are necessary for some, but probably not necessary for those who have neither the inclination or ability to understand.

 

[JoshO]

Well my 5600k plasma light wich is yellow like the sun and full spectrum grows acropora like weed.Night and day difference from blue light wich I’ve also used.Explain that.?

What par are you running? I think the point I've originally made has been lost through the discussion.
I'm simply stating that 250 par of 20k spectrum light is not equal in its energy volume to 250 par of 6500. That is a scientific fact.
What I'm saying is that we should not be using par as a blanket number when it comes to measuring light in our aquarium, but rather come up with an approximate guide based off spectrum or "temperature" which will be able to compare par v actual energy delivered.
I've no doubt, and confidently believe that the 6500 MH bulbs etc are growing machines. They will contain a lot of blue wavelengths. What I do believe though is that if you used a 20k MH and had the same par levels with your 6500 bulb, the 20k would grow coral faster if all other conditions are equal

 

[Acroguy]

What par are you running? I think the point I've originally made has been lost through the discussion.
I'm simply stating that 250 par of 20k spectrum light is not equal in its energy volume to 250 par of 6500. That is a scientific fact.
What I'm saying is that we should not be using par as a blanket number when it comes to measuring light in our aquarium, but rather come up with an approximate guide based off spectrum or "temperature" which will be able to compare par v actual energy delivered.
I've no doubt, and confidently believe that the 6500 MH bulbs etc are growing machines. They will contain a lot of blue wavelengths. What I do believe though is that if you used a 20k MH and had the same par levels with your 6500 bulb, the 20k would grow coral faster if all other conditions are equal

I believe quite the opposite, if yiu had equal PAR of 6500 or 20k the 6500 would grow Acropora faster.
I run the plasma at about 400-500 PAR.

 

[Acroguy]

The sun at midday has a PAR of around 2500 +- Acropora ( the ones we get in the hobby ) are mostly from shallow waters. 1- 10m ish depth.
At 2-3 m depth the PAR is very high still and the spectrum there is still quite “full”. So this is how I treat my acropora too.It’s not rocketscience. For some it is

 

[JoshO]

I believe quite the opposite, if yiu had equal PAR of 6500 or 20k the 6500 would grow Acropora faster.
I run the plasma at about 400-500 PAR.

What's your logic or reasoning behind this? I have a scientific study which used MH with colour temps of 5, 10, 15 and 20k...the 20k was the bulb that grew coral the fastest with all other variables kept as a constant. The frags used were all from the same 2 mother colonies, evenly divided between the bulbs.
That plasma delivering 500 par could be delivering the same volume of energy as a 20k at 300 par. It's something I'm trying to find, but when comparing wavelengths and energy delivered I think, could be wrong, 420nm was 1/3 higher in energy than 650nm

The sun at midday has a PAR of around 2500 +- Acropora ( the ones we get in the hobby ) are mostly from shallow waters. 1- 10m ish depth.
At 2-3 m depth the PAR is very high still and the spectrum there is still quite “full”. So this is how I treat my acropora too.It’s not rocketscience. For some it is

This is also evidence of what I'm saying, the levels of blue light energy in full spectrum will still exist. Par increases as we go from blue to full spectrum. However if par is kept at a constant then the energy is very different.

 

[JoshO]

In general, I think that the people who do not understand the debate or discussion usually do not have the experience or ability for nuanced thought to be on the same level as people who have both. The ones who lack tend to go towards non-useful phrases like "they all grow coral" like somehow that matters... all cars can get you to a destination, McDonalds or a balanced diet can keep you alive, etc. Most of the conversation is about the nuance, the over generalization, some details that people do not know, etc. They are necessary for some, but probably not necessary for those who have neither the inclination or ability to understand.

Very bluntly put, but very fitting

 

[jda]

Be careful of "studies." They can be misleading and incorrect- they can also be very good. For example, lots of people point to some of Dana Riddle's studies using porites but when I point out that these will grow in a fuge under a 6500k Screw-In CFL even he agrees that the findings are likely just for this species. He also found that PAR in Hawaii was around 1000-1200 during peak times, but I found nearly twice that which he agreed needs reconciled.

I would recommend blending what you read with what you see from smart people who keep tanks. I would listen to people like Adam at Battlecorals if you are into acropora. Dr. Joshi with nothing to sell is good too. Tim Herman grows corals like crazy. Abe does great too. Copps is legendary. There are others.

 

[MnFish1]

In general, I think that the people who do not understand the debate or discussion usually do not have the experience or ability for nuanced thought to be on the same level as people who have both. The ones who lack tend to go towards non-useful phrases like "they all grow coral" like somehow that matters... all cars can get you to a destination, McDonalds or a balanced diet can keep you alive, etc. Most of the conversation is about the nuance, the over generalization, some details that people do not know, etc. They are necessary for some, but probably not necessary for those who have neither the inclination or ability to understand.

Thanks

 

[Acroguy]

What's your logic or reasoning behind this? I have a scientific study which used MH with colour temps of 5, 10, 15 and 20k...the 20k was the bulb that grew coral the fastest with all other variables kept as a constant. The frags used were all from the same 2 mother colonies, evenly divided between the bulbs.
That plasma delivering 500 par could be delivering the same volume of energy as a 20k at 300 par. It's something I'm trying to find, but when comparing wavelengths and energy delivered I think, could be wrong, 420nm was 1/3 higher in energy than 650nm

This is also evidence of what I'm saying, the levels of blue light energy in full spectrum will still exist. Par increases as we go from blue to full spectrum. However if par is kept at a constant then the energy is very different.

My logic is that the sun is full spectrum, and Acropora grow a couple meters deep, or most of them do.If they would like the more blue or almost only blue wavelenghts they would grow much deeper,( some do).I am a simple guy.

 

[JoshO]

My logic is that the sun is full spectrum, and Acropora grow a couple meters deep, or most of them do.If they would like the more blue or almost only blue wavelenghts they would grow much deeper,( some do).I am a simple guy.

The sun is very much full spectrum, and as jda points out the par levels are absolutely incredible! I go back to my original point that if we reduced that par level to something similar to our reef tanks and compared to 20k at the same par id imagine we'd see differing growth levels.

 

[JoshO]

Be careful of "studies." They can be misleading and incorrect- they can also be very good. For example, lots of people point to some of Dana Riddle's studies using porites but when I point out that these will grow in a fuge under a 6500k Screw-In CFL even he agrees that the findings are likely just for this species. He also found that PAR in Hawaii was around 1000-1200 during peak times, but I found nearly twice that which he agreed needs reconciled.

I would recommend blending what you read with what you see from smart people who keep tanks. I would listen to people like Adam at Battlecorals if you are into acropora. Dr. Joshi with nothing to sell is good too. Tim Herman grows corals like crazy. Abe does great too. Copps is legendary. There are others.

Species specific studies can be very misleading, I totally agree. There is so much more to learn regarding lighting and I very much doubt we'll ever reach a point where we find the ideal lighting for a broad range of corals. But I'd like to think we could find a more accurate way of dialling in lighting than just par, hence the thread! The fact we are 9 pages deep is amazing as it just shows how much knowledge is out there (and also how much it varies).
I'm already someone who listens to just about every podcast from the people who have the experience

 

[jda]

@Lasse probably posted this in the pages before I joined, but if you want all of that blue spike to do anything, the more of the other colors and IR that you have, the more that it can be used. You need about equal amounts of red to move energy between the photosystems from all of the other sources, for example.

Yes, equal amount of a daylight spectrum will usually grow coral faster than the same amount from a heavy blue.

All of this said, if you like the heavy blue look and don't care as much about more growth and can live with a subset of corals, then who cares, right? There is some zen in this just being happy... it's not having what you want, it's wanting what you've got.

 

[jda]

But I'd like to think we could find a more accurate way of dialling in lighting than just par, hence the thread!

PAR sucks. No doubt.

It helped early LED adoption when even fewer understood what it was. Most of your LEDs today are made to pop a PAR meter and less to grow coral well - 400-700 visible spectrum range like somehow everything in the universe acts the same as human eyes. I know that if you add in UV and IR to LEDs, then all of a sudden costs go up, power goes up, surface heat goes up and the PAR meter does not pop more and the value-add proposition is less. This is mostly for the informed since the smart ones already know that a watt is a watt and what value that light has to corals, but those folks do not need to read made-up CoralLab articles anyway.