Now I would like to point out an even more dangerous light: the open-metal-frame indoor plant grow light. The "waterproof" lights I covered above are bad enough, but now people are starting to actually use indoor non-waterproof lights that not only have an open-air frame for water and algae to get into, but also have open 240/120 volt connections in the direct path of water:

Click image for larger version

Name:	open-frame-led.jpg
Views:	5079
Size:	57.3 KB
ID:	7812

Not only are these lights not going to last in the salt air humid environment of a sump, but out-of-the-box they create an extreme electrical hazard:

- The open frame allows water to drip down directly onto the high voltage components inside.
- Salt spray is going to get pulled through the unit, via the fans, which will corrode and/or short internal components.
- The open high voltage power cord connections are in the direct path of splashing, dripping, and even simple accidental dropping into the sump.
- Internal condensation, which already happens with the "sealed" type of lights when moisture eventually gets inside, is going to happen on the first day with these open-frame lights.
- Placing these lights into enclosed scrubber boxes reduces the circulation of cooling air, which further stresses the internal components.
- Using this type of light is the same as putting a toaster near a bathtub; all circuitry is directly exposed to water. Even if it's a UL rated, it's irrelevant.

Since these lights are clearly labeled (or should be labeled) as indoor-only, any usage of them in a worse-than-outdoor situation (such as a wet saltwater sump) puts a manufacturer or distributor in a very bad situation of negligence and possibly willful negligence. Please do not use these lights in a waterfall algae scrubber.