Originally Posted by allegori
As long as your LED fixture is protected from splashing and moisture, there shouldn't be any moisture issues. As for longevity, properly cooled LED's will last a long time. I always have glass tops on my tanks so my lights aren't exposed to water/moisture.
I bought a commercial product a year and half ago, a Vertex Illumilux LED strip, and had used it for about 7 months before going DIY. It worked just fine even though it felt really hot, but the manufacturer said it was acceptable for that fixture. It still works but is in a box now since I made a fixture myself and don't have a need for the extra light. In DIY builds, it is easy to replace any LED's if they burn out. Commercial fixtures are a bit more complicated to replace the LED's if they burn out unless you know how to reflow solder. So far my builds have had no problems.
Interesting... so it sounds a lot like a one-n-done solution, until the fixture is completely done for (unless you DIY, at which point you are able to build for your own open architecture). For $100 - $175 I would have no problem having a 10-year type fixture that just went into the trash when it burned out. Right now my Coralife CF fixture is a new ballast or wires about every other year, plus a set of bulbs right around the same time frame. That's about $65.00 a year I've been spending to keep my lights on before even talking power consumption. And, actually, I'm not into the cost savings as much as I am into just having one fixture... that works... period.