Mounting at an angle

[infinite0180]

Hey sps guys,

I mounted a couple frags at an angle awhile back. They are high up coming off the side of my rock. I have a single xr15 pro above them. Is it normal to see the undersides white and almost no polyp extension with the top sides facing the light looking great? The frags were originally on a rack growing straight up so they had nice color all the way around. We are talking about a purple stylo and a bubble gum digi...

Thanks

 

[Biokabe]

With a single-point light source like an XR15, yes, that is pretty normal.

Life is an optimization problem, especially when you're a sessile invertebrate. Photosynthetic tissue is expensive to maintain and is only justified by being able to create more energy than it consumes. With a point-source light like an LED, the undersides of rocks, corals, etc, tend to be comparatively dark, so that pretty photosynthetic tissue doesn't return much energy. Over time, the coral will shift its resources towards the productive areas and allow that portion of itself to die.

There really isn't a solution to it, other than getting a more diffuse light source. What size tank do you have?

 

[infinite0180]

With a single-point light source like an XR15, yes, that is pretty normal.

Life is an optimization problem, especially when you're a sessile invertebrate. Photosynthetic tissue is expensive to maintain and is only justified by being able to create more energy than it consumes. With a point-source light like an LED, the undersides of rocks, corals, etc, tend to be comparatively dark, so that pretty photosynthetic tissue doesn't return much energy. Over time, the coral will shift its resources towards the productive areas and allow that portion of itself to die.

There really isn't a solution to it, other than getting a more diffuse light source. What size tank do you have?

Thanks, thats exactly what i thought! Its an 18 inch cube. Red Sea Reefer Nano...

 

[jda]

This is why folks use many/more panels, add T5s or use different lights. ...not really all that easy in a nano. :)

It is not really normal in other situations, but it is normal for single point LED light sources.

Lasse had some great research that showed that green would penetrate tissue to get to the underside, making this problem more pronounced with blue-only LED settings. No idea if it is true, but you do see less of this is MH even on small reflectors - not as small of a light source as a single puck, but still smaller source than some.

 

[infinite0180]

This is why folks use many/more panels, add T5s or use different lights. ...not really all that easy in a nano. :)

It is not really normal in other situations, but it is normal for single point LED light sources.

Lasse had some great research that showed that green would penetrate tissue to get to the underside, making this problem more pronounced with blue-only LED settings. No idea if it is true, but you do see less of this is MH even on small reflectors - not as small of a light source as a single puck, but still smaller source than some.

I really wish there was a quality 18 inch t5 bulb available. Id add a few in a heartbeat. I wonder if going to a xr30 or xr30 pro would reduce the problem. I think before i do that ill wait and see how the coral adapts and grows for awhile...