Water quality isn’t static. The water coming into your home today isn’t necessarily the same as what was there six months ago — and it may not match what you’d find at your neighbor’s property two streets over. Baja’s water infrastructure, seasonal supply variations, and the near-universal use of cisterns all create conditions where quality can shift significantly over time.
Here are the situations where testing is clearly warranted — and the ongoing schedule that makes sense for most homes.
Test Immediately If:
You’re Moving Into a New Property
Whether you’re buying, renting, or building, a water test at a new property is the baseline everything else depends on. You have no history of the cistern’s maintenance, the plumbing materials used, or the neighborhood’s water quality. A test tells you exactly what you’re starting with.
You’ve Just Cleaned or Replaced Your Cistern
Post-service testing confirms that the cleaning was effective and that no contamination was introduced during the process. This is also the right time to sanitize the cistern and establish a new baseline.
Someone in the Home Has Had Gastrointestinal Illness
Recurrent stomach issues that don’t have a clear dietary explanation are sometimes traced to water contamination. A coliform test should be part of the investigation.
You Notice a Change in Taste, Smell, or Appearance
Any sudden change in your water’s characteristics warrants a test before you assume it’s temporary. New metallic taste, increased cloudiness, or an unusual smell all have measurable causes.
After Heavy Rain
Rain events can wash debris and contaminants into rooftop tinacos or ground-level cisterns, particularly if seals are degraded. Testing after significant rainfall is prudent in most Rosarito properties.
Test on a Schedule If:
You Have a Filtration System
An annual system check should include a water quality test to confirm the system is performing as designed. We check RO output TDS, verify UV controller readings, and run a basic field panel at every maintenance visit. If results have drifted from baseline, it tells us something needs to change — a cartridge is saturated, a membrane is declining, or source water quality has shifted.
You Don’t Have a Filtration System
Annual testing is the minimum for any unfiltered residential supply in Baja. This gives you a record of quality trends over time and catches problems before they affect health.
How Often Is Enough?
For most full-time residential properties in Rosarito with a maintained filtration system: annually, aligned with your filter service visit. For properties with older cisterns, higher occupancy, or a history of quality issues: every 6 months. For vacation properties or seasonal use: test when you return after an extended absence before resuming normal use.
