SPS growing Wide vs SPS growing Tall

[FlyPenFly]

I read an opinion recently that depending on the spectrum of light, SPS will grow a certain way.

That is, if the SPS receives too much light in the warmer spectrum it thinks it's in shallow water so it will spread sideways. If the SPS receives much more in the blue cooler spectrum it grows up and spreads sideways less because it thinks it's in deep water. It sort of makes sense but I'm skeptical.

Just curious if this reflect's other people's experiences and if there's been any actual study looking at this question.

 

[Reefer1225]

Interesting. I never heard that spectrum of light affects growth patterns. I would think it would be more about flow. Light spectrum I would assume would affect colors more.

 

[penfold2]

This sounds similar to the concept of plants using phytochrome to determine the ratio of red:far red light which tells them whether they are being shaded by other plants and need to focus on growing up or out. But this idea of coral growth form and color temperature doesn't make sense to me. Altering growth to avoid shade is one thing, but growing taller simply to reach shallower water seems quite unlikely. Things like hydrodynamics, ability to capture food, surface area exposed to sunlight, skeletal strength, etc are going to have a much greater impact on growth form than a very slight change in water depth. The only way a coral can significantly change its depth is by reproducing and colonizing new locations.

 

[FlyPenFly]

Actually I would guess that the logic is, Coral detects its only receiving blue light, Coral spends building points on branching higher instead of wider to receive more light.

 

[penfold2]

If you were to mount two 6" coral branches in the ocean, one pointing up and one laying flat, I'm pretty sure the horizontal one would grow faster. Even though the vertical branch is 6" higher at its tip, its illuminated surface area is minimized, while the horizontal branch has maximal illuminated surface area. I think a horizontal branch will always receive more light energy than a vertical branch. Growing upwards to receive more light definitely applies to shading situations, but probably becomes counterproductive in open water situations.

 

[dotcommer]

very interesting, would love to know if that is true.

 

[trueblackpercula]

I suspect this to be true as my corals were encrusting too much and not growing upwards. It was t until I turned down my intensity and changed my LEDs spectrum that I am now starting to see growth upwards.

I think this is a total true statement that you are making.

 

[penfold2]

I suspect this to be true as my corals were encrusting too much and not growing upwards. It was t until I turned down my intensity and changed my LEDs spectrum that I am now starting to see growth upwards.

I think this is a total true statement that you are making.

But corals frequently encrust before growing upwards. This kind of behavior is typical in all tanks regardless of light source. If someone had a collection of upward growing corals that flattened out after switching to a whiter light, that would be a bit more convincing, but even then it would be difficult to say whether it was intensity or spectrum that did it.

 

[trueblackpercula]

But corals frequently encrust before growing upwards. This kind of behavior is typical in all tanks regardless of light source. If someone had a collection of upward growing corals that flattened out after switching to a whiter light, that would be a bit more convincing, but even then it would be difficult to say whether it was intensity or spectrum that did it.

Could be just sharing what's going on in my tank now.

 

[Dugless]

I would think flow would dictate coral structure more so than light spectrum, No?

 

[icdeadpieces]

Flow will determine thicker vs thinner branches but light intensity determines upward growth vs branching.

 

[SaltyGoat]

We had a staghorn coral that would continually grow nearly to the surface, then branch horizontally. I suspect that the coral sensed the surface and branched horizontally to stay in the water. If this was because of flow, surface tension or light, I do not know.

This was grown under 3xMH 150w HQI (14K) and T5 combo (super actinic and royal blue). We had two inlets pointed across the back (one left, one right to cross) of a 180g but two Tunzie and two power heads adding supplemental flow.