solid state UV sterilizer LEDs

[ivanr]

I've been discussing UV sterilizers with a friend of mine with a Big Ick breakout.

I've used them in the past with success and I have a 24" version. I hated having to buy replacement bulbs.

But now that I am re-entering the hobby I am really surprised there is no manufacturer I can find that has built a solid state UV.

Which lends itself to a new DIY project. If you think about it there could be different ways to configure this. I am even thinking about building in strips of these into the bottom support I use under my glass sump. Just carve channels with a router into the plywood.

Now before anyone gets crazy, UV can strip you're retina and other damage. So any such application has to be safe.

Another way to do it would be like the Macro reactors with LED ribbon on both the inside and outside of a screened container.

 

[Spaced Cowboy]

There's more to it than just "UV". You need to look at the spectral wavelengths of the emitters, and AFAIK there isn't much of an overlap between LEDs and the-UV-we-actually-want.

Here's the comparison to your typical Mercury lamp that emits UV across a broad spectrum:

​

Most of the sterilisation happens because of light in the UVC range, which is (totally) absorbed by the earth's atmosphere under normal circumstances, so nothing has evolved to overcome it. Any transparent plastic or glass will absorb most of UVB, leaving just UVA. This is why my Emperor Aquatics Smart HO steriliser uses a quartz tube - quartz is pretty much transparent to the UV spectrum.

The UVA light isn't particularly effective at breaking down cells (otherwise we wouldn't be walking outside much) but that's where the LED spectrums are concentrated. If you can find LEDs with a UVC spectrum, that's a different matter (but you'll still want quartz as your barrier between them and the water). I'm not aware of any LEDs with such low wavelengths, but that doesn't mean they're not out there

 

[ivanr]

UV-C leds actually exist. Specifically for sterilization. Don't know how long they have been around but I have found several technical references. Wavelength 270-290 & 395-405 nm.
About 10 watts/meter. So a 3 meter strip sells for $150. Not sure of spectral power but I bet they are better than tubes. Also 30,000 hr life. So way better than tubes.

I forgot why the Quartz was there. But this might be easy enough just to form around a roll and replace the bulb in my current sterilizer.

But (and this is dangerous) I have in the past built a rig with several sterilizer bulbs and just hung these right over my sump and kill everything going by. Its just air and water and I concentrate this where the water is forced within an inch of the surface. I just use this when I have introduced new fish for about 2 weeks to make sure nothing starts up. So a flat rig with LEDs this way would work too and the nice thing is Leds radiate light in only one direction.

 

[oreo57]

UV-C leds actually exist. Specifically for sterilization. Don't know how long they have been around but I have found several technical references. Wavelength 270-290 & 395-405 nm.
About 10 watts/meter. So a 3 meter strip sells for $150. Not sure of spectral power but I bet they are better than tubes. Also 30,000 hr life. So way better than tubes.

I forgot why the Quartz was there. But this might be easy enough just to form around a roll and replace the bulb in my current sterilizer.

But (and this is dangerous) I have in the past built a rig with several sterilizer bulbs and just hung these right over my sump and kill everything going by. Its just air and water and I concentrate this where the water is forced within an inch of the surface. I just use this when I have introduced new fish for about 2 weeks to make sure nothing starts up. So a flat rig with LEDs this way would work too and the nice thing is Leds radiate light in only one direction.

INFO:
https://www.ledsmagazine.com/leds-s...n-demands-a-complete-uvc-led-picture-magazine

The key takeaway is the shorter the wavelength, the lower the flux, efficiency, and lifetime.