Fun fact about lighting

[Reef keeper 103]

400w mh cost 70 cents per day. And street lights are more efficient than leds (street lights are low pressure sodium). I would love to see a low pressure sodium light for a reef tank.

 

[Johnd651]

400w mh cost 70 cents per day. And street lights are more efficient than leds (street are low pressure sodium). I would love to see a low pressure sodium light for a reef tank.

I think it comes down to the wavelength. LPS ( low pressure sodium) is very yellow at 590nm. HPS (high pressure sodium) has a broader spectrum but still 570-620 nm. Would not be getting any of the blues.

 

[strich]

I don't have the personal experience to back this up, but I feel quite confident in saying that almost any home aquarium does not need to care one bit about the efficiency gained from optimizing wavelength of light. The water is too shallow to matter, and I cast doubt coral really grows faster under equally powerful lights at different nm, at the levels most run them at.

So yeah yellow sodium lights could work if you personally like that look lol.

 

[Johnd651]

I don't have the personal experience to back this up, but I feel quite confident in saying that almost any home aquarium does not need to care one bit about the efficiency gained from optimizing wavelength of light. The water is too shallow to matter, and I cast doubt coral really grows faster under equally powerful lights at different nm, at the levels most run them at.

So yeah yellow sodium lights could work if you personally like that look lol.

It's not about optimizing, it just something like a low pressure sodium lamp gives off no other wavelength. You would not get anything except 590nm, and coral need more then that.

 

[strich]

It's not about optimizing, it just something like a low pressure sodium lamp gives off no other wavelength. You would not get anything except 590nm, and coral need more then that.

Firstly, I don't have the science to back this opinion up: I don't think your entirely correct. I would bet coral can survive just fine on any singular visible light wavelength of a high enough wattage. Coral may survive better under a wider spread for sure, but I don't think they'd die under just 1.

 

[EeyoreIsMySpiritAnimal]

Firstly, I don't have the science to back this opinion up: I don't think your entirely correct. I would bet coral can survive just fine on any singular visible light wavelength of a high enough wattage. Coral may survive better under a wider spread for sure, but I don't think they'd die under just 1.

I guess the question is, do you want your coral to just "survive" or do you want it to be healthy?

 

[EeyoreIsMySpiritAnimal]

400w mh cost 70 cents per day. And street lights are more efficient than leds (street lights are low pressure sodium). I would love to see a low pressure sodium light for a reef tank.

(Fun fact, 400w costs the same regardless of what it's powering...)

 

[strich]

I guess the question is, do you want your coral to just "survive" or do you want it to be healthy?

I am genuinely curious to understand if what the difference would be, if at all, under home aquarium conditions. So many people bath their aquarium in that ugly blue light and all I can think of is: Does it even help? Theoretically yes, but practically? mmm.

 

[EeyoreIsMySpiritAnimal]

I am genuinely curious to understand if what the difference would be, if at all, under home aquarium conditions. So many people bath their aquarium in that ugly blue light and all I can think of is: Does it even help? Theoretically yes, but practically? mmm.

Avoiding "ugly blue light" is quite different than providing a coral with a single wavelength (590nm)

 

[oreo54]

. And street lights are more efficient than leds (street lights are low pressure sodium).

Low and High Pressure Sodium lights are the only light whose source efficiency compares to LEDs (values range between 50 and 160 lumens/watt for LPS and slightly less for HPS). They lose out to LEDs in many cases because their system efficiency is often much lower due to losses associated with omnidirectional light output and the need to redirect it to a desired area.

Sooo ..it depends.
Point is lps " may" produce more lumens/ watt but those lumens may not arrive where you want them to.

 

[oreo54]

Firstly, I don't have the science to back this opinion up: I don't think your entirely correct. I would bet coral can survive just fine on any singular visible light wavelength of a high enough wattage. Coral may survive better under a wider spread for sure, but I don't think they'd die under just 1.

They will def.suffer at 660nm only light .

Red Light - Good or Bad for Corals?

These are two papers from over 30 years ago examining spectral composition and coral photophysiology: Kinzie, R.A., P.L. Jokiel and R. York, 1984. Effects of light of altered spectral composition on coral zooxanthellae associations and on zooxanthellae in vitro. Mar. Biol., 78:239-248...

www.reef2reef.com

 

[strich]

They will def.suffer at 660nm only light .

Red Light - Good or Bad for Corals?

These are two papers from over 30 years ago examining spectral composition and coral photophysiology: Kinzie, R.A., P.L. Jokiel and R. York, 1984. Effects of light of altered spectral composition on coral zooxanthellae associations and on zooxanthellae in vitro. Mar. Biol., 78:239-248...

www.reef2reef.com

Thanks, that's a great thread on the topic! Your last post there with this paper makes it pretty clear that red or green on its own is not healthy. Interestingly yellow is...okay.