Is UV light a gimmick in LED Fixtures.

[Zacco]

Is UV light a gimmick In LED Fixtures, or do corals benefit by It?

UV light can be dangerous to all biological life so first we should examine the different wave lengths of UV light and their effects.

UV-a-315-400nm

UVA is the most commonly found form of UV, and is responsible for the tanning effect we see in our skin after some time spent in sun light.

UV-B- 280-315nm

UVB is the most dangerous of all forms of UV light. It possesses enough energy to wreak havoc on cellular DNA cells.
Overcast or cloudy skies are not enough protection from this type of UV light.

UV-C -200-280nm

This light is relatively safe to us because our atmosphere absorbs these rays. UV-C is found on germicidal lamps and UV Sterilizers where it will destroy
any biological life it comes in contact with.

So. Is UV Light Safe for Corals?

The answer is yes and it is beneficial to corals providing it is emitted at safe levels. Metal Halide and HQI lamps all emit a ton of UV-A and must be filtered out by glass or acrylic
cover or corals face the possibility of bleaching as Zooxanthellae cannot adjust to this light at a very fast pace. Since corals need sun light to make food, most live in shallow waters
near the ocean's surface which exposes them to UV-A and UV-B rays. Fortunately corals have the ability to make their own sunscreen to protect them and only allow safe ranges of UV which is beneficial
to the Zooxanthellae that reside in the corals.

Unlike metal halide lamps, UV LEDs in the 400-700nm range that are used in aquarium fixtures do not emit UV Radiation. The UV-A output can be controlled in Light Emitting Diodes thereby
providing safe and beneficial levels for the corals while still bringing out the beautiful fluorescence of corals. UV LEDs in the range of 380 - 400nm enters the visible range which produce a
small amount of UV, yielding a bluish purple light causing the corals to fluoresce while improving photosynthesis within corals.

So if your in the market of buying a new LED Fixture, it would be a wise and beneficial choice to buy a fixture that contains UV LEDs in it's array.

Sourced from Orphek:

 

[ReefLEDLights]

Is UV light a gimmick In LED Fixtures, or do corals benefit by It?

UV light can be dangerous to all biological life so first we should examine the different wave lengths of UV light and their effects.

UV-a-315-400nm

UVA is the most commonly found form of UV, and is responsible for the tanning effect we see in our skin after some time spent in sun light.

UV-B- 280-315nm

UVB is the most dangerous of all forms of UV light. It possesses enough energy to wreak havoc on cellular DNA cells.
Overcast or cloudy skies are not enough protection from this type of UV light.

UV-C -200-280nm

This light is relatively safe to us because our atmosphere absorbs these rays. UV-C is found on germicidal lamps and UV Sterilizers where it will destroy
any biological life it comes in contact with.

So. Is UV Light Safe for Corals?

The answer is yes and it is beneficial to corals providing it is emitted at safe levels. Metal Halide and HQI lamps all emit a ton of UV-A and must be filtered out by glass or acrylic
cover or corals face the possibility of bleaching as Zooxanthellae cannot adjust to this light at a very fast pace. Since corals need sun light to make food, most live in shallow waters
near the ocean's surface which exposes them to UV-A and UV-B rays. Fortunately corals have the ability to make their own sunscreen to protect them and only allow safe ranges of UV which is beneficial
to the Zooxanthellae that reside in the corals.

Unlike metal halide lamps, UV LEDs in the 400-700nm range that are used in aquarium fixtures do not emit UV Radiation. The UV-A output can be controlled in Light Emitting Diodes thereby
providing safe and beneficial levels for the corals while still bringing out the beautiful fluorescence of corals. UV LEDs in the range of 380 - 400nm enters the visible range which produce a
small amount of UV, yielding a bluish purple light causing the corals to fluoresce while improving photosynthesis within corals.

So if your in the market of buying a new LED Fixture, it would be a wise and beneficial choice to buy a fixture that contains UV LEDs in it's array.

Sourced from Orphek:

Whoa...I've been to a few rodeos and even a donkey show and find this statement rather interesting and rather off on an academic level.

UV has not been used in the the hobby as MH Lights that emit it have UV shields and DE MH Bulbs have a UV Shield in the Fixture.

UV< 400nm will degrade plastic so its something you do not want. UV LEDs <400nm often have issues with the lenses burning out. Some have UV resistant lenses which is less affected so the UV Rays can interact with your Acrylic tank or silicon sealed glass tank...

Corals do have pigments that reflect UV A B & C.

That said UV LEDs in the range of 380-400nm do yield a slight fluoresce, however given the intensity of the latest 380-400nm LEDs its moot and an inefficient attempt in LED Light Design.

Corals do respond well if acclimated to High Intensity LED Lights. The 420-450nm range offer significant fluoresce.

SPS Corals respond in various ways to light. On subject is Photo Inhibition and Photo Rejection.

Photo Inhibition depending on species starts between 350-500 PAR. Photo Rejection is after.

These are the pigments that corals produce to reflect the excess light and is what makes an average looking coral beautiful given a light intense enough...400 watt MH Equivalent

Corals are exposed to over 2000 PAR in a Tropic Tidal Pool. They produce pigments that reflect both UV and Regular light. More often than not the pigments are the same or very similar. They even produce a mucus which keeps them from drying out in exposed air.

"So if your in the market of buying a new LED Fixture, it would be a wise and beneficial choice to buy a fixture that contains UV LEDs in it's array" is like saying "BRAWNDO gots what corals crave...Its got electrolytes!"

Gimmick...The Proof is in the pudding...Look at established 3-5 year old reefs and judge for yourself.

Bill
ReefLEDLights

 

[racin2438]

All I can add is after having some corals under a good quality LED units (ACAN) Prism panels some corals just did not do as well and there color was off (dull).

I switched some to frag tank and used a Kessel A350W and saw some good improvement

Then replace the Kessel to the new Ecotechmarine X15R, Pro with UV LEDS....and know seeing major growth and coloration.

So UV is good...

 

[hart24601]

The problem is everyone calls violet LEDs UV when they are not. You don't see vary many fixtures that have true UV LEDs, but somehow everyone got started calling anything below royal blue "UV". There are now a couple that are right at 400nm, but even calling that a true UV LED is still pushing it a little bit.

 

[Zacco]

Very true hart24601 . Violet leds are not true UV LEDs.

 

[hart24601]

Are there any fixtures that use true UV LEDs? I know AI has a 400nm, but even that is really pushing what someone would call a UV LED. At least they are not calling 420nm UV, but with 400 being the cuttoff of UV, a 400nm LED emission should be split between UV and non-UV. I would consider that to be "near UV" while something like 385nm would be a true UV, but I don't think I have seen any reef lights with those.

 

[evolved]

The problem is everyone calls violet LEDs UV when they are not.

Exactly!

 

[ReefLEDLights]

I prefer the term Violet or Hyper Violet for LEDs 400-440nm.

Bill