DIY diffusers for LEDs

[dantimdad]

@Matt Carden you will get some diffusion for sure, but, I am not convinced this is the way to go.

Try it, maybe it'll work.

I am going to test it and not be a nay sayer. ;)

 

[Diamond1]

@Matt Carden you will get some diffusion for sure, but, I am not convinced this is the way to go.

Try it, maybe it'll work.

I am going to test it and not be a nay sayer. ;)

Following along to see what you come up with.

 

[EMeyer]

In the plat biology world its fairly well established that you don't put plastics in the light path if you can avoid it. They age and start absorbing wavelengths they shouldnt. I am seeing a lot of recommendations for acrylic, but no one is addressing this. As far as I understand this, it has to be glass.

With respect, I dont think theres any physical basis for believing egg crate does much to diffuse light. I get that it "looks" that way but I dont think this is supported by any data (e.g. PAR values)

I tried taking lenses off. The light cannot penetrate far enough with decent PAR if you remove the lenses. I measured this extensively. Remove lenses on a black box and hang it over >12 inches of water, you cant break 200 PAR even at max power. Removing lenses worked great for a shallow frag tank but nowhere near enough PAR in a deeper display.

 

[dantimdad]

In the plat biology world its fairly well established that you don't put plastics in the light path if you can avoid it. They age and start absorbing wavelengths they shouldnt. I am seeing a lot of recommendations for acrylic, but no one is addressing this. As far as I understand this, it has to be glass.

With respect, I dont think theres any physical basis for believing egg crate does much to diffuse light. I get that it "looks" that way but I dont think this is supported by any data (e.g. PAR values)

I tried taking lenses off. The light cannot penetrate far enough with decent PAR if you remove the lenses. I measured this extensively. Remove lenses on a black box and hang it over >12 inches of water, you cant break 200 PAR even at max power. Removing lenses worked great for a shallow frag tank but nowhere near enough PAR in a deeper display.

Well we will have to agree to disagree on this one.

On my diy LEDs I don't run lenses at all. Have always gotten good growth

There are folks on this forum who have removed them and have beautiful sps in their tank.

I will take measurements soon on my lastest modified black box. with and without diffusion.

 

[EMeyer]

Well we will have to agree to disagree on this one.

On my diy LEDs I don't run lenses at all. Have always gotten good growth

There are folks on this forum who have removed them and have beautiful sps in their tank.

I will take measurements soon on my lastest modified black box. with and without diffusion.

To clarify, I'm not taking a stand about whether you can run a tank without lenses. People have different preferences for target light levels.

I just know that with the boxes I tested, PAR values got very low in deep water (>12") without any lenses. Maybe a four-fold reduction in maximum PAR. If you have PAR values that disagree with this I'd be curious to hear about them. Can you get >200 PAR in >12" water without lenses? I could not. With diffusers I could, but I suspect the spectrum was off because of the plastic.

 

[mch1984]

I'm going to be following along on this, doing a tank for my dad and he ordered a viperspectra black box. It's a 24" x 24" x 16" tank and I'm going to be hanging the light 12" above just like it recommends. I was wanting to try some form of defuser and then started reading about taking lenses off and everything else. I think I'll just hang out here and see what the testing shows. Really curious.

 

[dantimdad]

I am not saying about what numbers I am getting until I measure. I just know that they work. Now, I would bet that at 12" I am getting no where near 200 par. But, despite what you see in pitch videos, you don't need it.

I can extend the photo period if needed when PAR is lower. What I am after is the correct spectrum and the correct amount of light in a photoperiod. If I keep corals that need high PAR all the time, then I can keep them higher in the tank.

 

[b4tn]

I dont have a par meter (Wish I did) but I keep my lights 12" above the water, I get no disco ball affect at all just shimmer like when I had halides, and I get great growth in both SPS and LPS. I am running OR T247 lights at 60 blue 40 white but getting ready to ramp up on the blues. The intent was to build these to keep my jumpers in the tank and they have saved my Corris Wrasse on multiple occasions lol. But a pleasant side affect is that they seem to spread the light better. Its just clear netting from amazon and a screen door kit. They have held up for 3 almost 4 years now.

This is pre partial tank crash with the covers on.

 

[mch1984]

I was going to ask about that, there will be a screen top on my dads tank. Was kind of wondering if you got the same effect from it.

 

[Millennium reefer]

Could it be that we are comparing apples to oranges here? Black box is a generic term for a long list of Chinese led light makers that all make a similar style box but, those manufacturers led's all use different diode's and lenses. I believe some makers have the diodes that diffuse the light and others use a lens to diffuse the light. I could be wrong, but I think this is the case because some use a white opic lens, some it is clear and some colored. I am interested in whatever you'll come up with but would like to know the brand of the light for comparison purposes.

 

[dantimdad]

Could it be that we are comparing apples to oranges here? Black box is a generic term for a long list of Chinese led light makers that all make a similar style box but, those manufacturers led's all use different diode's and lenses. I believe some makers have the diodes that diffuse the light and others use a lens to diffuse the light. I could be wrong, but I think this is the case because some use a white opic lens, some it is clear and some colored. I am interested in whatever you'll come up with but would like to know the brand of the light for comparison purposes.

Possibly, but, it the truest sense of the term "Black Box" they all use diodes from the same couple of manufacturers and are really close in spec. Bridgelux is probably about 80% of the LEDs used. Yes, where they differ (despite being called off the shelf lenses by a big website that investigates) is the lenses. If you look even the brand name lights, you can find their lenses for sale "off the shelf". There must be 1000 different lenses available.

The combination of different lenses has struck now. I have seen fixtures that combine COBs and individual LEDs under different lenses to reach a desired effect with interesting results.

It's a buyer's market when it comes to finding something that works for an individual right now. You can literally find 100s of different configurations and looks.

And we won't even get into the changes when you start modding them...

 

[CMatlosz]

I've used this directly on Rapid LED aurora puck kits for years, never had an issue. They make a few different kinds with varying degrees of diffusion. It's made for professional lightning like studio setups, etc. I never had a par meter to check for loss but I turned up about 10% on all channels and never saw a difference from the animals in the tank. Way better visual appeal for me with far less disco.

It's like a thin flexible mat material, I cut it down to the size equal to the splash guards and attached it with tape on the ends. Works great.

https://www.amazon.com/Rosco-Cinege...9561070&sr=8-7&keywords=light+diffusion+sheet

 

[dantimdad]

Thanks for that link. Added to the list to test.

 

[Lingwendil]

That stuff looks promising for sure! Might have to try a piece, unless anybody has a 6" square scrap to donate to science. I'll try it in my 6" makers sink nano rig.

 

[EMeyer]

Anyone ever try that material? The picture looks almost transparent.

Been tinkering with this over the last year or so, removing lenses is my preferred solution for shallow frag tanks but I find it impractical for deep tanks (I end up with very low PAR at 100% intensity, like <200 PAR). So I have gone back to HD plastic diffuser on deep tanks. It produces ~30% reduction in PAR but measurably more even light levels across the tank. (My goal is not to reduce some subjective visual "disco ball" effect, but to provide equal PAR across the tank).

Anyone make any new progress on this recently?

 

[ceejay2018]

I wonder how low iron solar glass would work? I have a stack of it at home. Full sheets. It has a diffused look to it.

 

[oreo54]

Frost your own glass..
Amazon product

There are others, most are technically extremely dangerous..Like Hydrofloric acid..

Difference between etched and frosted glass | Peterlee Glass

Peterlee Glass is the north east’s leading commercial glass suppliers. In this blog, we explain the difference between etched and frosted glass and when it can be used.

www.peterleeglass.com

 

[theatrus]

I wonder how low iron solar glass would work? I have a stack of it at home. Full sheets. It has a diffused look to it.

Probably great. However, some may have coatings applied for IR/UV side so if you're looking at passing the deeper violets it may attenuate.

 

[ceejay2018]

Probably great. However, some may have coatings applied for IR/UV side so if you're looking at passing the deeper violets it may attenuate.

I may try some out and check out the spectrum inside the tank. I know it’s anti-glare but not sure about spectrum blocking characteristics of it. If it works out I have a lot of it.

 

[dantimdad]

@ceejay2018 where are you located?

I would like to buy some of that glass off you.