Lighting Break Mode during day time. Benefit? (fluval marine and reef 2.0)

[bsfmaximus]

I just picked up a couple of gently used 24” marine and reef 2.0 fluval led lights and “WiFi” controller. Good deal. I was running 24 and 18 inch current USA marine orbits on my 54g corner tank previously.
I am hoping because of spectrum and wattage that this is an upgrade. I’ve sucessfully been growing sps under the marine orbits. Any confirmation of this being a positive change?
My main question: is there any benefit of a mid-day “break” mode? The controller offers this to ramp down lighting for a period of time but I can’t find anything about a benefit behind that. I’m currently using it to transition to the stronger lights but in a week or two, is there any reason to keep using it?

 

[Homelander]

I just picked up a couple of gently used 24” marine and reef 2.0 fluval led lights and “WiFi” controller. Good deal. I was running 24 and 18 inch current USA marine orbits on my 54g corner tank previously.
I am hoping because of spectrum and wattage that this is an upgrade. I’ve sucessfully been growing sps under then marine orbits. Any confirmation of this being a positive change?
My main question: is there any benefit of a mid-day “break” mode? The controller offers this to ramp down lighting for a period of time but I can’t find anything about a benefit behind that. I’m currently using it to transition to the stronger lights but in a week or two, is there any reason to keep using it?

No benefit that I could really think of. @Dana Riddle any thought on this mid day break?

 

[Nano sapiens]

In the natural environment corals do not receive a steady stream of sunlight each and every day. Often, there are break periods due to clouds/water vapor, volcanic eruptions, etc. In theory, having break periods allows the coral to more effectively deal with any excess build up of oxygen radicals created by it's symbiotic zooxanthellae.

In practice, I can only speak to my own personal experience. I've been using the 'cloud' feature of my controller for quite some time at it's least frequent setting and the corals have responded well.

 

[Homelander]

In the natural environment corals do not receive a steady stream of sunlight each and every day. Often, there are break periods due to clouds/water vapor, volcanic eruptions, etc. In theory, having break periods allows the coral to more effectively deal with any excess build up of oxygen radicals created by it's symbiotic zooxanthellae.

In practice, I can only speak to my own personal experience. I've been using the 'cloud' feature of my controller for quite some time at it's least frequent setting and the corals have responded well.

I guess I would need to know more about this break mode. Are the lights turning off? Or just dimming down in intensity for a set amount of time?

 

[Dana Riddle]

Arrrgggghhhh! The answer I don't like to make - it depends. Here's why. If light intensity exceeds the Saturation Point (usually 200-400 micromole/m2/sec, less for some Montiporas, more for Tridacna clams), protective xanthophylls (acting as 'pressure relief valves' for photosynthesis) can shunt light energy away from the photosynthetic apparatus. However, this doesn't happen instantly - about 20 minutes is required for protective xanthophylls to ramp up. So, if your light intensity is high, and you give the corals a mid-day break for over half an hour or so, the protection offered by xanthophylls is lost when the lights return to high output and they (corals/zoox) could suffer. If the light intensity is low, xanthophyll protection isn't needed to begin with, and loss of light equals loss of photosynthesis, but wasn't this the point to begin with?

 

[bsfmaximus]

Arrrgggghhhh! The answer I don't like to make - it depends. Here's why. If light intensity exceeds the Saturation Point (usually 200-400 micromole/m2/sec, less for some Montiporas, more for Tridacna clams), protective xanthophylls (acting as 'pressure relief valves' for photosynthesis) can shunt light energy away from the photosynthetic apparatus. However, this doesn't happen instantly - about 20 minutes is required for protective xanthophylls to ramp up. So, if your light intensity is high, and you give the corals a mid-day break for over half an hour or so, the protection offered by xanthophylls is lost when the lights return to high output and they (corals/zoox) could suffer. If the light intensity is low, xanthophyll protection isn't needed to begin with, and loss of light equals loss of photosynthesis, but wasn't this the point to begin with?

What you said made sense but... A loss of photosynthesis was the point to begin with?
I don't know but I don't think so. My present goal is to acclimate my coral to the new light, then do whatever makes them the healthiest, prettiest, and fastest growing. I assumed the break mode might be a good method to acclimate. I ramp up to full intensity for an hour in the morning. I've got another hour running full, then I drop down during the break to 70%. Then back to full intensity for 2 hours in the evening. I plan to increase the break intensity ever day or two by 5%. If this plan is flawed, please let me know. I literally pulled it out of thin air, just an excuse to use my new "toy" aka break mode.
Maybe you can tell me if I am being overcautious in general. Maybe my upgrade is nominal and doesn't even require acclimation.... My tank is a 54g corner. I've got two of these 24" Fluvals over it now, they are 34 watts each. My previous lights, the marine orbits, were 18 and 23 watts with 8,000K, 12,000K, and 445nm/460nm lights. These Fluval lights consists of 400nm, 420 nm, 440nm, 460nm, 620nm, and 15K. I've got euphyllias down close to my sand bed and SPS in the top third of the tank.

 

[Nano sapiens]

Arrrgggghhhh! The answer I don't like to make - it depends. ?

'It depends' should be printed on every piece of reef aquarium related literature

Under higher lighting, I can see where longer breaks (over 20 minutes) could be an issue regarding protective xanthophylls, but infrequent short breaks every once in a while for a few minutes could be beneficial for the coral in dealing with oxygen free radicals. Under medium/lower light these processes are much less of an issue (if at all) and this is why I don't use a high output light regime for my long established small mixed reef.

Ralph.

 

[Dana Riddle]

Quote: So, if your light intensity is high, and you give the corals a mid-day break for over half an hour or so, the protection offered by xanthophylls is lost when the lights return to high output and they (corals/zoox) could suffer. If the light intensity is low, xanthophyll protection isn't needed to begin with, and loss of light equals loss of photosynthesis, but wasn't this the point to begin with?[/QUOTE]
That statement made sense when I typed it at 4 a.m., but upon re-reading it - It should have read: That wasn't the point to begin with. In other words: Loss of photosynthesis isn't the goal.

 

[Dana Riddle]

Why didn't I state that so succinctly? The goal of every aquarist should be providing optimal conditions, including lighting, hence exceeding the Compensation Point but not exceeding Saturation and certainly avoiding Chronic Photoinhibition. Dynamic Photoinhibition (xanthophyll protection) is dependent upon a pool of xanthophylls that are created in response to very high light and should help avoid production of excessive oxygen radicals and hydrogen peroxide. These can be detoxified by enzymes (SODs and others) but their production on dependent upon flow (thinning boundary layer and sufficient supply of metals found in the enzymes (copper, zinc, others if memory serves.) Does this happen in an aquarium? It depends.

'It depends' should be printed on every piece of reef aquarium related literature

Under higher lighting, I can see where longer breaks (over 20 minutes) could be an issue regarding protective xanthophylls, but infrequent short breaks every once in a while for a few minutes could be beneficial for the coral in dealing with oxygen free radicals. Under medium/lower light these processes are much less of an issue (if at all) and this is why I don't use a high output light regime for my long established small mixed reef.

Ralph.

 

[[Cameron]]

Recovery is an important aspect of growth but tanks generally get that on a day/night cycle. All these features on the LED fixtures are interesting but MH/T5 designs are proven and most lack any special programming.

Corals particularly SPS are adaptive but they dislike sudden change. If you want to keep them growing, stay relatively consistent. If you change anything expect a decline in growth until they figure out the new scheme. Even in the "old days" when changing out worn out MH bulbs for new ones would send some corals into hiding. I think these cool LED cycles are fine when used consistently but I wouldn't expect a huge jump in growth.

 

[bsfmaximus]

That statement made sense when I typed it at 4 a.m., but upon re-reading it - It should have read: That wasn't the point to begin with. In other words: Loss of photosynthesis isn't the goal.

Got it. That makes sense. Thanks! I will probably adjust my acclimation and future plans accordingly. I suppose if there is questionable benefit and a real chance for negative effects, then I'd prefer to error on the side of caution.

 

[Nano sapiens]

In the natural environment corals do not receive a steady stream of sunlight each and every day. Often, there are break periods due to clouds/water vapor, volcanic eruptions, etc. In theory, having break periods allows the coral to more effectively deal with any excess build up of oxygen radicals created by it's symbiotic zooxanthellae.

In practice, I can only speak to my own personal experience. I've been using the 'cloud' feature of my controller for quite some time at it's least frequent setting and the corals have responded well.

Why didn't I state that so succinctly? The goal of every aquarist should be providing optimal conditions, including lighting, hence exceeding the Compensation Point but not exceeding Saturation and certainly avoiding Chronic Photoinhibition. Dynamic Photoinhibition (xanthophyll protection) is dependent upon a pool of xanthophylls that are created in response to very high light and should help avoid production of excessive oxygen radicals and hydrogen peroxide. These can be detoxified by enzymes (SODs and others) but their production on dependent upon flow (thinning boundary layer and sufficient supply of metals found in the enzymes (copper, zinc, others if memory serves.) Does this happen in an aquarium? It depends.

I didn't do much better this morning as I should have just typed 'medium' light instead of 'low' light. Problem with these types of ambiguous terms is that one person's 'low' is another person's 'medium', one person's 'high' is another's 'medium' etc. largely depending on the type of organisms that they are keeping.

IME, after 30+ years of reef keeping I learned the hard way that pushing corals too hard with too much light intensity/duration is a lot more detrimental long term than providing a bit less than the maximum of what I believe (based on experience, both mine and others') that the coral can realistically take. Perhaps a bit subjective, but there it is

Ralph.

 

[Dana Riddle]

Yes, agreed - terms such as 'high' and 'low' light are so subjective as to be useless. You might recall George Smit's article in FAMA many years ago that. more or less, described 'high' light as that produced by a few standard 40-watt fluorescent tubes, specifically including a full spectrum Vita-Light. One of the reasons I bit the bullet and shelled out $1,500 for a Li-Cor PAR meter. The more I learn, the less I know.

 

[bsfmaximus]

The more I learn, the less I know.

It's All Too Much? Beatles and/or George Harrison fan?

 

[Nano sapiens]

Yes, agreed - terms such as 'high' and 'low' light are so subjective as to be useless. You might recall George Smit's article in FAMA many years ago that. more or less, described 'high' light as that produced by a few standard 40-watt fluorescent tubes, specifically including a full spectrum Vita-Light. One of the reasons I bit the bullet and shelled out $1,500 for a Li-Cor PAR meter. The more I learn, the less I know.

Oh yes, I remember those early lighting articles! I used to use 40w NO bulbs waaaay back in the day (as many as I could fit) and any trick in the book to reflect as much light back down into the tank. Then came HO/VHO! Fun times.

Although we know a lot more than we used to about lighting these animals, it's still perplexing sometimes (at least to me) when what we think should work doesn't always jive with what we see actually happening (usually with a particular specimen). So many variables...

Questions like this from the OP are really good to get the mind-juices flowing in an attempt to come up with a concise answer based on the latest scientific knowledge .