How fast and how much should I ramp up my LED fixture?

[Sailfish]

I just got my new Coral Box M1-30 V2 LED fixture, from fish-street. It uses 3W chips, most Cree chips, and has 95 degrees optics. Link: http://www.fish-street.com/coralbox_m1_led_aquarium_lighting?category_id=126

From just playing with it for a few days, my first impression of it is great! The colors in the tank really pops and the light is easy to control with four individually adjustable channels.

 

My only concern is how much and how fast I should ramp up the intensity.

The tank is a 16G "BioCube-ish" mixed reef, with some SPS on top and LPS/softies closer to the bottom. The light is mounted in the lid, putting it about 4" over the water surface. The tank is 12" tall, not counting the lid.

 

Currently, I have the light set to:
- W: 20%

- B: 14%

- RGB: 3%

- Violet: 3%

I suspect this is much lower then what my SPS needs in the long run, but I have been afraid of starting more intense.

How do I know the level of intensity from my lamp that my corals will grow the fastest and thrive best under?

[farkwar]

Most likely NOT real Cree LEDs, first off.

 

Without a PAR meter, you need to watch your corals reaction as to light intensity.

 

What were they use to before you bought them or bought the light?

 

Blue would be, can be, the highest intensity. Violets too, you can turn them up.

 

Keep your whites down from the start and work up, to your taste and what your corals like.

[Sailfish]

Most likely NOT real Cree LEDs, first off.

 

Without a PAR meter, you need to watch your corals reaction as to light intensity.

 

What were they use to before you bought them or bought the light?

 

Blue would be, can be, the highest intensity. Violets too, you can turn them up.

 

Keep your whites down from the start and work up, to your taste and what your corals like.

Hmm, I would think a large international vendor like fish-street would not write Cree LED chips, if that was not the case

 

The soft corals that have been in my tank for about 6 months are used to 2x24W 10.000-12.000 K T5 lighting. This has been my emergency lighting, since my previous sub-par LED lamps went out. Two days ago I purchased 10 new frags from a buddy. 8/10 are SPS, that comes from a strongly lit T5/LED mixed 106G tank. The frags have been positioned at the bottom of his tank for the last week or so, if that makes any difference.

 

I seem to recall people complaining on violets burning their corals, when turned to high. Is this only true for "true violets", not normal violets?

 

I know that the whites are the main factor in light intensity received by the corals. That is why I have not turned them up higher then 20%. How do I know when to stop ramping up the whites?

 

I have a 2 week window of opportunity, before I go back to my university. By then I need to have set the intensity so that the corals survive to Christmas, when I come back and can continue to tinker with it.

Suggestion to how fast and how far I should ramp up the whites, before I leave?

[Nano sapiens]

Without a PAR meter it's a bit of a guessing game. It can take months to get it 'just right'. Best you can do is observe your corals each day to see if they are looking 'normal' as you slowly increase intensity.

 

'White' LEDs add PAR, but some of the wavelengths are unusable for photosynthesis so PUR is lower. They are really blue LEDs that have a coating which is designed to add some of 'warmer' wavelengths, many of which corals don't need for photosynthesis (although 'red' is used for photosyntheses), but do cause some pigments to develop. A lot of the 'white' is really for us so that colors are rendered more 'naturally'. Typically, they are run at lower intensity than the violets and blues which the coral uses for photosynthesis.

 

 

A good rule of thumb is 5% total intensity increase/week.

[jedimasterben]

Hmm, I would think a large international vendor like fish-street would not write Cree LED chips, if that was not the case

You realize that Fish-Street really only sells knockoff/Chinese products, right? Cree doesn't sell Cree-branded diodes outside of the US AFAIK. Almost all are produced in China, but that's about it.

 

A good rule of thumb is 5% total intensity increase/week.

This. Start low (around 25-35%) and then do the above.

 

I have a 2 week window of opportunity, before I go back to my university.

You should not have purchased new equipment if you're going to spend so much time away so soon after starting to use it.

[farkwar]

...large international CHINESE vendor like...

 

Fixed that for you.

 

Yes, of course, they are fake.

 

Mainland Chinese vendors or manufacterers do not have to, nor do they, comply with American(or European) trademarking or copyrighting laws.

 

Regarding intensity, do what you want to do.

I started my violets on my cluster at about 80, then up to 100, iirc.

Your corals dont need violet, turn them off, your corals will fine.

 

True ultra violet light destroys DNA. All of my violets are 405nm and above. Water does block a lot of true UV light.

 

White light grows crap algae pretty well. I tune my whites to my production of crap algae, mostly.

 

Ben's the expert on LEDs, listen to him.

[Scorched]

So this light?

 

www.aquasunrise.com

 

Its commonly referred to the SL-A001 everywhere else online.

 

I actually just bought the 90cm version for my tank last week. It was delivered Monday and I have been pretty impressed with it. Im glad I went straight to the manufacturer as I saved almost $200

 

I don't know if the fixture uses true cree leds or not, but I had a Chinese fixture with just white and blue leds for 2 years that was "3W Crees" and I had growing colorful coral. I wanted to upgrade to something with a similar design but had built in control. I'll try to share my experience as the corals adjust.

 

If anyone else has this light I made an excel document to chart the setpoints so its easier to see.

https://www.dropbox.com/s/7r1y0oiflr...ightGraph.xlsx

It could be modified for other controllable lights if you tweak my inputs and calculations.

[Sailfish]

Without a PAR meter it's a bit of a guessing game. It can take months to get it 'just right'. Best you can do is observe your corals each day to see if they are looking 'normal' as you slowly increase intensity.

 

'White' LEDs add PAR, but some of the wavelengths are unusable for photosynthesis so PUR is lower. They are really blue LEDs that have a coating which is designed to add some of 'warmer' wavelengths, many of which corals don't need for photosynthesis (although 'red' is used for photosyntheses), but do cause some pigments to develop. A lot of the 'white' is really for us so that colors are rendered more 'naturally'. Typically, they are run at lower intensity than the violets and blues which the coral uses for photosynthesis.

 

 

A good rule of thumb is 5% total intensity increase/week.

Had never heard of PUR before. Have to check it out

Ok, I have always thought that it is the white LEDs that are the main contributors to a light fixture's PAR output. And as you mention in your post and I have read elsewhere, people use PAR values to select the best spots for certain corals.

Is it the white or blue LEDs that tend to burn corals?

 

You realize that Fish-Street really only sells knockoff/Chinese products, right? Cree doesn't sell Cree-branded diodes outside of the US AFAIK. Almost all are produced in China, but that's about it.

 

This. Start low (around 25-35%) and then do the above.

 

You should not have purchased new equipment if you're going to spend so much time away so soon after starting to use it.

I know that, but I reacted when they state clearly and without any purposeful spelling mistake "Cree XP White / Royal Blue / Red / Green with Violent and Moonlight LED Chips". Usually knockoffs either copy a product and slaps a new logo on it (E.g. FS-01 Dosing Pump knockoff of Bubble Magus dosing pump) or they copy a product and brands it almost identical to the original (Eg. Oakley - Okey, Ray-Ban - Rey-Ban...). Here they actually states "Cree" and even mentions the actual chip model, "XP". I don't know what to think.

 

What is most important that I start out low (25-35%) on, white or blue channel?

 

I know, but the T5 light would not have been enough for 3 more months, I think I needed a replacement quick.

 

...large international CHINESE vendor like...

 

Fixed that for you.

 

Yes, of course, they are fake.

 

Mainland Chinese vendors or manufacterers do not have to, nor do they, comply with American(or European) trademarking or copyrighting laws.

 

Regarding intensity, do what you want to do.

I started my violets on my cluster at about 80, then up to 100, iirc.

Your corals dont need violet, turn them off, your corals will fine.

 

True ultra violet light destroys DNA. All of my violets are 405nm and above. Water does block a lot of true UV light.

 

White light grows crap algae pretty well. I tune my whites to my production of crap algae, mostly.

 

Ben's the expert on LEDs, listen to him.

I see what you did there

 

Hmm, look at my reflections above and let me know what you think

 

We use UV to sterilize tools, in the hospital When I wrote "true violets" I meant the LED chips that go by that branding, over "super violet" or simply "violet".

 

How fast do you notice the growth of crap algae, if you surpass the "white limit"?

 

Yeah, Ben has come to my rescue multiple times. I know that he knows his stuff!

 

So this light?

 

www.aquasunrise.com

 

Its commonly referred to the SL-A001 everywhere else online.

 

I actually just bought the 90cm version for my tank last week. It was delivered Monday and I have been pretty impressed with it. Im glad I went straight to the manufacturer as I saved almost $200

 

I don't know if the fixture uses true cree leds or not, but I had a Chinese fixture with just white and blue leds for 2 years that was "3W Crees" and I had growing colorful coral. I wanted to upgrade to something with a similar design but had built in control. I'll try to share my experience as the corals adjust.

 

If anyone else has this light I made an excel document to chart the setpoints so its easier to see.

 

 

 

https://www.dropbox.com/s/7r1y0oiflr...ightGraph.xlsx

It could be modified for other controllable lights if you tweak my inputs and calculations.

From what I can see it is the exact same light, except I do not have WiFi controllability. My light has a remote that communicates with the unit by infrared.

Also, I see that the model that corresponds to my light (the smallest one) has the red and green LEDs in center, while my unit has them more to the sides (red towards one side, green towards the other).

 

How deep is your tank?

How high off the water is your light suspended?

What is the optics on your unit?

What corals do you keep, and where in the tank are they placed?

How much did you pay for the 90cm version?

 

THANKS FOR THE HELP AND REPLIES PEOPLE!

[Nano sapiens]

Had never heard of PUR before. Have to check it out

Ok, I have always thought that it is the white LEDs that are the main contributors to a light fixture's PAR output. And as you mention in your post and I have read elsewhere, people use PAR values to select the best spots for certain corals.

Is it the white or blue LEDs that tend to burn corals?

PUR (Photosynthetically Usable Radiation) is much more important to corals than PAR. However, accurate measuring devices to measure PUR are typically much too expensive for the average hobbyists, so we use inexpensive PAR meters. A PAR meter gives you a reading of ALL the wavelength radiation within the visible spectrum (400nm - 700nm), whether corals actually use the wavelengths or not. So, thinking in terms of the light source's PUR wavelengths reaching the corals is more relavent than PAR.

 

To simplify, the violet to blue-green and red spectums stimulate photosynthesis. Too much of these spectrums will over stimulate the coral's zooanthellae population. In mild cases the coral will eject the excess in an attempt to regulate since one of the byproducts of the zooanthellae is oxygen (some of it in the form of hydrogen peroxide, ouch!). In severe cases of rapid over lighting, the coral will eject a large portion (or even all) of it's zooanthellae in an effort to protect itself from oxygen oversaturation.

[farkwar]

The Philips new UV Z's DO go into the UV range. They have like different 25 wavelength models now, about half of them go into the UV range. They are selling the UVs for medical and identification uses.

 

Before this, LEDs billed as UV were mostly merely violets(with a few exceptions). You'd see a lot of posting and hand wringing about this difference in the past.

 

I was just making the point that true UV light, if it passes through the water, will most likely kill animal and plant tissue. For clarification.

 

I have 2 Kessil 350s over my frag tank. Im currently fighting a bout of bryopsis. Ive turned the whites almost off. I have a lettuce nudibranch (sea slug). Ive stopped the increased growth of bryopsis, by turning down the whites. Apparently the lettuce is photosynthetic. Its been lethargic for the last 24 hours just sticking to the glass at the top rim, slacking its job.

 

Im going to turn the whites back up, see if I can wake it up.

[Nano sapiens]

I have a lettuce nudibranch (sea slug). Ive stopped the increased growth of bryopsis, by turning down the whites. Apparently the lettuce is photosynthetic. Its been lethargic for the last 24 hours just sticking to the glass at the top rim, slacking its job.

 

Im going to turn the whites back up, see if I can wake it up.

 

Yes, they are. If I remember correctly, they collect the algae cells and keep them alive in their bodies for a few weeks. They have to continuously replace the cells to keep the photosynthesis going so that they can beneift from the products produced..

[farkwar]

I don't know what to think.

I think that unless otherwise proved, any American, European, Japanese, or Taiwanese named product coming out of Mainland China, is fake or counterfeit.

 

For example, you can buy "Meanwell" power supplies from LEDGroupbuy. They are the same "Meanwell" power supplies on eBay for half the cost of LGB, being sold by Chinese vendors.

 

I bought a couple of the American "Meanwell" power supplies from "American" LGB thinking that these could not or would not be counterfeit. These have the actual Meanwell logo on them, no derivation of the name. The power supplies I bought are fake, AND I overpaid LGB by double, to be duped. I dont know if I should call these counterfeit, Taiwanese Meanwell doesnt even make a version, anything like these, of these crappy fire hazards, as far as I can tell.

 

On the otherhand. I can buy a Holga camera with free shipping from China, on eBay, for $25. I can buy the same camera at a camera shop in Sacramento for $65. Or from a US/European website for $85 plus shippling. I know that I am getting a real Holga from the Chinese seller, because its just as crappy a Holga as its supposed to be. It is, in this case, the US sellers trying to rip me off, not Chinese counterfeiters.

 

I just purchased a Meanwell SCW05B -12 from a Chinese vendor. I can't find a US vendor which stocks this model, right now im running with 50/50 its fake. Dunno, dont have it yet.

 

To Ben or Clive, if you know of a US vendor for the Meanwell SCW05B-12(the 24vDC to 12vDC one), that has it in stock, ill need that if this Chinese one is fake. Tia.

[farkwar]

Yes, they are. If I remember correctly, they collect the algae cells and keep them alive in their bodies for a few weeks. They have to continuously replace the cells to keep the photosynthesis going so that they can beneift from the products produced..

 

This is Stinky, thinks shes in a union or something.

 

http://s1078.photobucket.com/user/RichardSperry/media/20140822_184400.jpg.html'>

 

Turned the whites back up to 50, we shall see if that motivates her. If not I have 12 in a shopping cart at LA waiting to take her job. Or a 2 watt laser.

[Tamberav]

I am with farkwar on this one. China has counterfits of everything it seems like. Some items they copy every detail and even make a matching box and packing material. One thing that comes to mind are toy models. They don't re-brand it or change the name to something similar, they straight up copy everything.

[Nano sapiens]

I am with farkwar on this one. China has counterfits of everything it seems like. Some items they copy every detail and even make a matching box and packing material. One thing that comes to mind are toy models. They don't re-brand it or change the name to something similar, they straight up copy everything.

 

I wonder if the low grade chinese companies produce counterfeits of higher grade chinese products?

 

With the 'World-wide' economy we have today there will no end to this counterfeiting business. Too many people just don't care as long as it's cheap enough.

[Scorched]

From what I can see it is the exact same light, except I do not have WiFi controllability. My light has a remote that communicates with the unit by infrared.

Also, I see that the model that corresponds to my light (the smallest one) has the red and green LEDs in center, while my unit has them more to the sides (red towards one side, green towards the other).

 

How deep is your tank?

How high off the water is your light suspended?

What is the optics on your unit?

What corals do you keep, and where in the tank are they placed?

How much did you pay for the 90cm version?

 

THANKS FOR THE HELP AND REPLIES PEOPLE!

 

Even the LED setup on their website is outdated. They sent me their latest layout with the red and green more spaced and a different pattern to the violets

 

Its 18 blues, 16 whites, 4 violets, 3 ultra violets, 2 green, 2 red, 3 moon (bluish cyan)

I swapped 3 violets with 410nm violets to get a little more spectrum.

In hindsight I kind of wish I put all the reds on channel 4 and put the cyans on 3 in place of both red and green.

90 degree optics. If they had a choice I would have put 120 diffuse optics on all of the LEDs on channel 3.

 

I paid $255 ($170 less than fishstreet)

 

My tank is shallow so it gives me an advantage, but I'd believe both lights I've had could grow colorful sps at 12-14" underwater. in the 2 foot range it would probably be fairly weak. I suspended my previously light with cables over a foot above the water, and this new light has legs that are about a foot tall. I would have used suspension cables again but we changed office building and the tanks new location is in a room with what seems like 20' ceilings.

[farkwar]

 

I wonder if the low grade chinese companies produce counterfeits of higher grade chinese products?

 

With the 'World-wide' economy we have today there will no end to this counterfeiting business. Too many people just don't care as long as it's cheap enough.

Yes, there are at least 2 Chinese Bubble Magus doser ripoffs.

 

And seeing as how Bubble Magus skimmers are half price on reef street, maybe their skimmers too. And the SCA skimmers are poor quality ripoffs of BM skimmers. The SCA 301 is pure junk, btw. Lots of admirers here of them. Its like one person buys a shit sandwich, and then tells everyone how good it us, so they buy a shit sandwich too. They dont want to admit they are eating a shit sandwich, so they too give it good reviews.

 

And this continues until someone buys the shit sandwich, "Hey this is a shit sandwich."

"No its not, its good, what do you know?"

 

The new Reef Octopus Elite skimmers are direct copies of the Vertex Omega skimmers, which are oddly made in China too. Maybe not oddly, it seems as though if the overlords and masters are German and American, Chinese slaves can actually make decent product. When slave masters are Chinese, they make a shit ton of shit sandwiches.

[Sailfish]

PUR (Photosynthetically Usable Radiation) is much more important to corals than PAR. However, accurate measuring devices to measure PUR are typically much too expensive for the average hobbyists, so we use inexpensive PAR meters. A PAR meter gives you a reading of ALL the wavelength radiation within the visible spectrum (400nm - 700nm), whether corals actually use the wavelengths or not. So, thinking in terms of the light source's PUR wavelengths reaching the corals is more relavent than PAR.

 

To simplify, the violet to blue-green and red spectums stimulate photosynthesis. Too much of these spectrums will over stimulate the coral's zooanthellae population. In mild cases the coral will eject the excess in an attempt to regulate since one of the byproducts of the zooanthellae is oxygen (some of it in the form of hydrogen peroxide, ouch!). In severe cases of rapid over lighting, the coral will eject a large portion (or even all) of it's zooanthellae in an effort to protect itself from oxygen oversaturation.

Hmm, I didn't know that the corals expelled the zooanthellae as a protection against overproduction of free radicals! I always thought that they simply got "sunburnt", and that the coral cells became uninhabitable for the zooanthellae.

 

So in fact, it is the blue channel I should be careful pushing too hard too fast, not the white channel (disregarding potential algae overgrowth)?

 

The Philips new UV Z's DO go into the UV range. They have like different 25 wavelength models now, about half of them go into the UV range. They are selling the UVs for medical and identification uses.

 

Before this, LEDs billed as UV were mostly merely violets(with a few exceptions). You'd see a lot of posting and hand wringing about this difference in the past.

 

I was just making the point that true UV light, if it passes through the water, will most likely kill animal and plant tissue. For clarification.

 

I have 2 Kessil 350s over my frag tank. Im currently fighting a bout of bryopsis. Ive turned the whites almost off. I have a lettuce nudibranch (sea slug). Ive stopped the increased growth of bryopsis, by turning down the whites. Apparently the lettuce is photosynthetic. Its been lethargic for the last 24 hours just sticking to the glass at the top rim, slacking its job.

 

Im going to turn the whites back up, see if I can wake it up.

Is the blue light alone sufficient to grow your corals?

 

I am with farkwar on this one. China has counterfits of everything it seems like. Some items they copy every detail and even make a matching box and packing material. One thing that comes to mind are toy models. They don't re-brand it or change the name to something similar, they straight up copy everything.

Then the quality should be identical too

 

Even the LED setup on their website is outdated. They sent me their latest layout with the red and green more spaced and a different pattern to the violets

 

Its 18 blues, 16 whites, 4 violets, 3 ultra violets, 2 green, 2 red, 3 moon (bluish cyan)

I swapped 3 violets with 410nm violets to get a little more spectrum.

In hindsight I kind of wish I put all the reds on channel 4 and put the cyans on 3 in place of both red and green.

90 degree optics. If they had a choice I would have put 120 diffuse optics on all of the LEDs on channel 3.

 

I paid $255 ($170 less than fishstreet)

 

My tank is shallow so it gives me an advantage, but I'd believe both lights I've had could grow colorful sps at 12-14" underwater. in the 2 foot range it would probably be fairly weak. I suspended my previously light with cables over a foot above the water, and this new light has legs that are about a foot tall. I would have used suspension cables again but we changed office building and the tanks new location is in a room with what seems like 20' ceilings.

That is a big saving!

I didn't know that you could customize the lamp before order Something to remember for later...

 

My tank is only 12" deep, so then I think I will have no problem growing SPS close to the top and LPS/softies towards the bottom. I will probably have to keep my light quite a bit lower then your stated values. Thanks, for the details!

[Nano sapiens]

Hmm, I didn't know that the corals expelled the zooanthellae as a protection against overproduction of free radicals! I always thought that they simply got "sunburnt", and that the coral cells became uninhabitable for the zooanthellae.

 

So in fact, it is the blue channel I should be careful pushing too hard too fast, not the white channel (disregarding potential algae overgrowth)?

 

Corals create MMAs (microsporine like amino acids) that act as 'sunscreen'. 'MAAs are effective antioxidantmolecules and are able to stabilize free radicals within their ring structure. In addition to protecting cells from mutation via UV radiation and free radicals, MAAs are able to boost cellular tolerance to desiccation, salt stress, and heat stress.' This is one of the mechanism corals have to deal with UV and free radicals, but of course it has it's limits. Massive ejection of Zooanthellae is a coral's last ditch effort to save itself from imminent destruction.

 

As I mentioned, the 'white' is mostly blue with smaller amounts of other wavelengths thrown in, so it does contribute to PUR, too, Just not as much as pure violet or blue in emitters of similar power and efficiency. So you need to watch your intensity of violets, blues and also whites.

[farkwar]

 

 

Is the blue light alone sufficient to grow your corals?

No.

 

And like I said, it put Stinky on the picket line.

 

Makes sense, if she has bryopsis chloroplasts in her, cutting white light slows growth of bryopsis, it would cut her production of energy as well.

 

With whites at 50, shes back to work. The white Kessil channel, theres a bunch if different LEDs per channel, and I havent stared at it long enough to determine what colors are in each of the 2 channels.

 

 

Its funny, I couldnt grow algae in my ATS. Now my whole tank is effectively an ATS. When I pull a wad of bryopsis out, its exporting that mass of nutrients. When Stinky eats it, it just changes form (sea slug poop) which has to be mechanically removed.

[farkwar]

My tank is only 12" deep, so then I think I will have no problem growing SPS close to the top and LPS/softies towards the bottom. I will probably have to keep my light quite a bit lower then your stated values. Thanks, for the details!

Light intensity follows the law of squares. Inverse Square Rule/Law.

 

Half the distance, 4 times the light.

Double the distance, 1/4 the light.

 

Thats for point source light.

 

Diffused light breaks the rule a bit. If at your 12", your SPS is doing fine, but your burning your LPS at the bottom, diffuse the light, and turn up intensity a little to account for the lost efficiency if the diffusion panel. I have challices that are 14" below my SPS that burn.

[Sailfish]

Corals create MMAs (microsporine like amino acids) that act as 'sunscreen'. 'MAAs are effective antioxidantmolecules and are able to stabilize free radicals within their ring structure. In addition to protecting cells from mutation via UV radiation and free radicals, MAAs are able to boost cellular tolerance to desiccation, salt stress, and heat stress.' This is one of the mechanism corals have to deal with UV and free radicals, but of course it has it's limits. Massive ejection of Zooanthellae is a coral's last ditch effort to save itself from imminent destruction.

 

As I mentioned, the 'white' is mostly blue with smaller amounts of other wavelengths thrown in, so it does contribute to PUR, too, Just not as much as pure violet or blue in emitters of similar power and efficiency. So you need to watch your intensity of violets, blues and also whites.

I saw Bear Grylls use the "sunscreen" from a huge leather coral, to protect his skin when stranded on a deserted tropical island

 

Wow. that is so cool! The MMAs comprise the mucus that the coral produce when taken out of the water, then? I didn't know that they produced it while submerged also. I thought that they only needed their "sunscreen" while being left in dry air, during low tide (No water to filter away UV). But since the zooanthellae produce free radicals, then they need protection all the time.

 

No.

 

And like I said, it put Stinky on the picket line.

 

Makes sense, if she has bryopsis chloroplasts in her, cutting white light slows growth of bryopsis, it would cut her production of energy as well.

 

With whites at 50, shes back to work. The white Kessil channel, theres a bunch if different LEDs per channel, and I havent stared at it long enough to determine what colors are in each of the 2 channels.

 

 

Its funny, I couldnt grow algae in my ATS. Now my whole tank is effectively an ATS. When I pull a wad of bryopsis out, its exporting that mass of nutrients. When Stinky eats it, it just changes form (sea slug poop) which has to be mechanically removed.

So the white LEDs still produce the most PUR, although they also produce more unwanted radiation that algae thrive on?

 

That is reef irony for ya! I hope to get an up flow algae turf scrubber going in my next 24G setup. That will be the only form of nutrient export, other then water changes. At least that is the plan... and plans change surprisingly fast in this hobby

 

Light intensity follows the law of squares. Square Rule Law.

 

Half the distance, 4 times the light.

Double the distance, 1/4 the light.

 

Thats for point source light.

 

Diffused light breaks the rule a bit. If at your 12", your SPS is doing fine, but your burning your LPS at the bottom, diffuse the light, and turn up intensity a little to account for the lost efficiency if the diffusion panel. I have challices that are 14" below my SPS that burn.

This is very interesting and useful knowledge! So, if you could grow colorful SPS at 12-14", then I should divide your light intensity scheme values by 4, to get my approximate values for growing SPS at 6-7"?

 

What do you suggest as diffusing material?

[farkwar]

If your light is 24 inches from the target, and has intensity of 40 at the target.

 

If you move the light source to 48 inches, intensity will be 10 at the target.

 

If you move the light source to 12 inches, intensity will be 160 at the target.

 

This is in a vacuum with a point source light.

 

You can use whatever type of screening you desire. There is privacy film you can adhere to your light. Home Depot diffusion screens, say diamond plate style, even white eggcrate works (thats what its made for).

 

Dmitry uses this on his RLL lights

http://www.acrylite-shop.com/US/us/two-sided-velvet-texture-cx2tw0dadf1/acrylite-satinice-dp9-colorless-0f00-dc-nq1trtv8pp0~p.html

 

Which is what I would use. It has 91% pass through efficiency.

[Sailfish]

If your light is 24 inches from the target, and has intensity of 40 at the target.

 

If you move the light source to 48 inches, intensity will be 10 at the target.

 

If you move the light source to 12 inches, intensity will be 160 at the target.

 

This is in a vacuum with a point source light.

 

You can use whatever type of screening you desire. There is privacy film you can adhere to your light. Home Depot diffusion screens, say diamond plate style, even white eggcrate works (thats what its made for).

 

Dmitry uses this on his RLL lights

http://www.acrylite-shop.com/US/us/two-sided-velvet-texture-cx2tw0dadf1/acrylite-satinice-dp9-colorless-0f00-dc-nq1trtv8pp0~p.html

 

Which is what I would use. It has 91% pass through efficiency.

Yes, so you agree that I should divide your intensity values by a factor of 4, when my SPS corals are twice as close to the light (6-7" vs. 12-14")?

 

That film looks nice. I see that the one you linked to is "two sided velvet texture". They also have the same in "one sided velvet texture". What does that mean? Texture on both sides vs. only one?

[farkwar]

I will say that you will need to adjust your intensity and distance based on your light and your animals reaction to the light.

 

Without a PAR meter with waterproof probe, you need to use your eyes. I dont have a PAR meter, you can rent one from here...

 

https://reefledlights.com/shop/par-meter-rental/

 

Re diffusion screen material. Choose what you like best. It hardly critical. I just used some 600 grit sandpaper to make mine so far, with good results (not pro quality). The one I linked has a high transmission efficiency, they have all kinds of different types. Its a German company, I would believe their numbers are accurate. They will cut to size, btw.