LED's should last many times longer than Halogen bulbs! Ask the PB how long he's been installing them and how often they need to be replaced.

Safety might be a consideration. I suppose a low-voltage Halogen would be pretty safe but LED even safer. I strongly suggest transformer isolation however, and even a GFI clear back at the source. However I'll link this thread to a few fellow pool owners and get back to you

What does PB stand for

PB=Pool Builder.

Led's should last around 50,000 hours. So if you ran it for 3 hours a day you would get about 45 years out of it.

Fwded as promised above from correspondent Len Glensk:

It all depends upon the effect you're trying to get with the pool. Yes, some of the halogen units save energy...but won't necessarily give you the brightest output. Some of the new units with LED allow for color changing wheels to run in the canister creating different visual effects which can be nice. In any case all systems should be connected to a GFI circuit to prevent any potential shock hazard to users of the pool.

Color changing wheels? That's the old school method of getting color from basically a traditional single colored halogen or xenon bulb.

LED pool lights are basically arrays of many colored LED's (White, Red, Green and Blue). To get magenta, the red and blue LEDs are turned on while the green and white LEDs are turned off. To get a lighter shade of magenta, just turn on a few of the white LEDs.

Because of this flexibility, many color patterns can be created with a microprocessor controlling the on/off state of the individual LEDs. Also, this means that if a single LED fails, the rest of the array continues to work (at least with the Pentair).

Pentair also makes white-only LED light that basically omits the color LEDs to get higher lumens (brighter output). This light has an array of 32 white LEDs.

In all cases, an LED is many, many times less likely to "burn out" than a halogen/incandescent bulb. Also, there is not a single LED Pool Light (Pentair, Nexxus, Hayward, Jandy, et al) that I know of that uses a color wheel. Here's a link to the parts breakdown for a Pentair Intellibrite LED Pool Light.

Hate to say it, your PB is not well-informed about LED technology nor LED pool lights.