UV LED over tank

[StirCrazy]

Originally Posted by sphelps

Certainly no expert on lighting but my understanding of UV light is that it relates to spectrum wavelengths. UV-A is in the range of 315-400nm, UV-B in the range of 280-315nm and UV-C in the range of 200-280nm. Ultraviolet light is by definition not visible so a true UV led would not omit visible light however some of the "UV" LEDs on the market peak at 380nm so they omit light in both visible and invisible spectrum most of which falls under UV-A so for the purpose of our hobby and application calling these UV LEDs seems accurate. Any thing above 400nm however is just plain violet despite often referred to as UV.

I'm only aware of LEDs in the upper UV-A range so the damage they can preform from UV radiation is virtually nothing and are completely safe. Lighting like metal halides have much more light found in the UV-A range therefore requiring UV shields to prevent damage.

yup you are correct, but the UV-A range is a generally harmless range and some of it is visible. (although it appears very very dim.) when people are talking about UV LEDs generally they are not talking about real UV LEDs as at 50 bucks a shot for a reasonable strength one they are not a cheep options. good ones are in the 120 buck range.

rather we are talking about "Near UV" or true violet as they are referred to, which have a peek about 417. the reason for including these is the royal blue LEDs peek around 450 nm and are very week around 400.

so in reality a true violet just is a common sense addition to any LED system to ensure complete coverage from 400nm up.

now people have been playing with the 365 to 400nm range and personally if I could find a affordable LED in that range I would add it also as that area does have some effects I enjoy also. This range is also included in any decent MH bulb.

Steve