Single Point Light Source for Acropora sp.?

[Justin Aretz]

My apologies if youve seen this post elsewhere, i am trying to gather as much real world experience based opinions as possible. Attached is a cut section of a new build that i've dreamed about for ages. The objective in aesthetic is to recess a powerful light in the ceiling, to eliminate anything above the tank. My concern is the single point light source. The way that i currently have it designed, the light will have a 30 degree lens on it. The light will be mounted 4' above waters surface, and 6' above sand bed. My question, do you think this single point source of light will be detrimental to acropora health, growth, or coloration?

 

[jda]

Lots of shadows as stuff grows. Also, the distance will cut down on output - even with tight lenses, the light will spill a lot.

I doubt that you will get much real-world help on this one, but I hope so.

 

[Justin Aretz]

Lots of shadows as stuff grows. Also, the distance will cut down on output - even with tight lenses, the light will spill a lot.

I doubt that you will get much real-world help on this one, but I hope so.

Dana Riddle gave his input and has given me some form of reassurance. With the 30 degree lens, I am certain I can get ample par. The shadowing worries me but it's a risk that will need to be taken to experiment with this. If in two years another light must be added, it's not too big of a project. This single point source lighting coming from the ceiling has been a dream of mine for ages now, so i'm willing to gamble a bit to perfect it.

 

[Dana Riddle]

I wouldn't be overly concerned about self-shading. Based on chlorophyll concentration analyses of corals in Hawaiian tide pools, zooxanthellae concentrations are highest in shaded areas, especially in conditions of high light. I've got a slide in a PowerPoint presentation that demonstrates that. I'll find that and post later.

 

[Marquiseo]

My apologies if youve seen this post elsewhere, i am trying to gather as much real world experience based opinions as possible. Attached is a cut section of a new build that i've dreamed about for ages. The objective in aesthetic is to recess a powerful light in the ceiling, to eliminate anything above the tank. My concern is the single point light source. The way that i currently have it designed, the light will have a 30 degree lens on it. The light will be mounted 4' above waters surface, and 6' above sand bed. My question, do you think this single point source of light will be detrimental to acropora health, growth, or coloration?

This shouldn't be any different from any pendant style fixture like Kessils. Your biggest hurdle will be finding a powerful enough fixture to shoot adequate par to the SPS corals from that distance; the further away from the surface, the less par.

 

[hart24601]

It will be interesting to see how it goes, I’m sure it will be set up like this, but ideally the light will just start to spill over the top, so you will get reflections off the glass that help a bit with shading. Few people mount lights too low so the cone of light isn’t reflected.

 

[TerraFerma]

If you run one of the Orphek canons you should be good to go. That said I don't think they are meant to be run in an enclosed area as you show on your diagram.

 

[Dana Riddle]

Zoox chlorophyll analyses of those found in a shaded area of a Porites stony coral. Not shown is the top - that area exposed to full sunlight. All of those measurements were below the detection limit of the instrument (40 milligrams per square meter.)

 

[Justin Aretz]

This shouldn't be any different from any pendant style fixture like Kessils. Your biggest hurdle will be finding a powerful enough fixture to shoot adequate par to the SPS corals from that distance; the further away from the surface, the less par.

though orphek refuses to give me PAR readings as to avoid mismanaged expectations, the Amazonas 320 with 30D lens and XP LED clusters, i have loosely assumed i will get ample par out of this light build for this application. i am excited. I hope this opens doors for how we approach reefing in the future. My current SPS tank has 5 LED fixtures, 2x 2 bulb T5 fixtures, not to mention 2x cooling fans all suspended from a half rusted steel rack, with aluminum tracks to hold the actual light fixtures, and 9 different wire paths tangled floating above it. Could it be cleaner? aboslutely. Will this new concept be the cleanest? i hope so!!!!!

 

[Justin Aretz]

Zoox chlorophyll analyses of those found in a shaded area of a Porites stony coral. Not shown is the top - that area exposed to full sunlight. All of those measurements were below the detection limit of the instrument (40 milligrams per square meter.)

wow. that is very interesting.

 

[Justin Aretz]

If you run one of the Orphek canons you should be good to go. That said I don't think they are meant to be run in an enclosed area as you show on your diagram.

It will be vented. Will start at 100 CFM and work my way up from there.