9,000 Hours...
... is the recommended service life of the UV bulb integral to our water system. Yesterday it let me know that the jig was up, so today I changed the lamp. Haven't yet quite calculated when the next replacement will be, but I have already ordered a replacement bulb, using the same philosophy as that used by experienced gas grillers who always have a backup tank.
Tower of power. Beans on the menu tonight—thanks, of course, to irrigation.