LED Hot Spots?

[NanaReefer]

Anyone ever experience this issue with their LED's? One particular area where anything and everything fades and or bleaches?
What is the cause? Is there a fix? Please, I'm struggling here and I'm at a loss. I have a beautiful tank, with so many new and beautiful corals. Yet the middle of my tank is bare. I just can't put anything there

 

[KingOfPain86]

What kind of LED light? How far off the water is it?

 

[Coralsdaily]

A bit more info? type of LED, distance to the water, intensity setting you have on?

 

[NanaReefer]

40B. 180w 120 degree optics, full spectrum, fully programable. 3w Bridgelux diodes. 12 1/2" from waters surface. Whites at 12% intensity max. Ramping up/down from 10am till 4:30pm. Blues at 55% intensity max. Ramping up/down from 8:30am till 7:00pm.
All corals are doing great on the outer areas as you can see by placement. It is that area between the 2 islands that I cannot put anything. I have a Seneye Reef monitor, par meter. If it's true or close the par reading in that area is 265+ on the sand bed.

I tried putting my Birds Nest there and almost killed it. Yet put it higher up, off to the side, like in the pic and it's thriving!

 

[Zacco]

Has alot to do with the lense covering the LED's and how it blends and disperses the light. IMO Kessil has the edge on the market with their Dense Matrix LED technology.

 

[Zacco]

Hot spots also occur when manufacturers place their LED's too far apart from each other and put a single lense over each LED. Ever see individual colors in a tank? A hot spot of white, A hot spot of blue, A hot spot of red, ect.

 

[Zacco]

Example of poor design. LED's are too far apart from each other and not tightly compacted together in a small group. Correct blending/ mixing and Even Light Dispersion can not occur IMO.

 

[Keithcorals]

The problem is the optics I've fixed this problem on similar lights by removing some of the optics. This will give wider spread and and less output directly under the light. The only other option is to raise the light higher to give you a more even spread. Hope that helps

 

[Zacco]

I agree. Only way to fix your hot spot is to raise the light to soften the hot spot your fixture is emitting.

 

[NanaReefer]

Thank you! I may need to go the optics removal route. If I can raise the unit it would only be by a couple inches at most, pretty limited.

 

[g6gang]

The problem is the optics I've fixed this problem on similar lights by removing some of the optics. This will give wider spread and and less output directly under the light. The only other option is to raise the light higher to give you a more even spread. Hope that helps

How do your safely remove the optics without damage to the led? Is there a special tool?

 

[Keithcorals]

Depending on the fixture they are usually just held on by the fixture. I don't know exactly what your fixture looks line but if it is the black box typ the glass or acrylic shild in front of the leds is likely what's holding the optics in place. If you take it apart the optics will likely come right off. If you don't like the effect you can take off more optics or put some back on. If you posted a pic of the fixture Id have a better idea of how they are held in place.

 

[Nevil]

I have the same light and I'm having similar issues. Would you remove all the optics or just some of them? Which ones if just some of them.

 

[g6gang]

Depending on the fixture they are usually just held on by the fixture. I don't know exactly what your fixture looks line but if it is the black box typ the glass or acrylic shild in front of the leds is likely what's holding the optics in place. If you take it apart the optics will likely come right off. If you don't like the effect you can take off more optics or put some back on. If you posted a pic of the fixture Id have a better idea of how they are held in place.

Thanks Keith the optics just simply pulled off. I originaly thought you had to wiggle them off and ended up losing one led that I had to re-solder on. But then figured out you just needed to pull straight off. I lke the light soooo much better without the optics. I will most likely increase the intensity now to compensate, but the spread is very mcuh more uniform.

I did actually notice a green light in a section of my rock and just thought it may have been a reflection.

BTW - do you know how to tell the difference on the optics if it is a 90degree or a 120degree? My light was supposed to hve both, but all of the optics looked exactly the same to me. Just curious to know what they actually are, To me the outsides did not seem to be 120%.

Here is my thread on the mod:

https://www.reef2reef.com/forums/reef-radiance/194370-removal-optics.html

 

[Keithcorals]

I don't know a good way to tell what the angle of an optic is but I prefer no optics to optics of any angle so I never really tryied to figure it out. Maybe someone can tell us if there is a way to tell.

 

[miamiangler]

I have the same light as nana , it`s easy to remove they pull off .I replaced my 90`s with 120`s . Nana, birds nest don't like high light ,all my birds are near the edge of the tank PAR`S IN THE 100`S Clams would look good in the center sand bed .

 

[NanaReefer]

Here's my worry with removing any/all optics. I cannot raise my unit any higher. (12 1/2" from surface) What can I expect by removing just the 4-6 center ones? Spread wise? Am I going to have a beam look?

 

[miamiangler]

I have my light 10 Inches of the water and ramp up to 40% white and 60%blue for 30mins so far my corals are doing well also my 60 gal is 27inches deep .Par reading with my seneye on surface close to 550=600. 12 inches down Par from center 240to300.

 

[Keithcorals]

Here's my worry with removing any/all optics. I cannot raise my unit any higher. (12 1/2" from surface) What can I expect by removing just the 4-6 center ones? Spread wise? Am I going to have a beam look?

The optics cause the beam look. If you remove them you get a wider spread so you would not want to raise the light you might even be able to lower it . If you only remove the center ones you would get a more even light and less of a hot spot directly under the light.

 

[NanaReefer]

I have my light 10 Inches of the water and ramp up to 40% white and 60%blue for 30mins so far my corals are doing well also my 60 gal is 27inches deep .Par reading with my seneye on surface close to 550=600. 12 inches down Par from center 240to300.

Wait, do you have optics or not?