Honolulu vs Waikiki Water Quality

Side-by-side water quality comparison for two Hawaii cities.

If you are comparing Honolulu and Waikiki water quality - whether moving, choosing between the two, or curious about a relative's water - here is what the data shows.

Hardness comparison

Honolulu has significantly harder water at 80 PPM versus Waikiki at 20 PPM, a difference of 60 PPM. Waikiki residents generally do not need any water softening equipment.

Water sources and why they differ

Water sources differ: Honolulu draws from Groundwater (basalt aquifer), while Waikiki uses Pearl Harbor Aquifer. The mix of groundwater and surface water explains much of the hardness difference.

What this means for you

Not sure what your specific situation needs? Take the quiz to get a recommendation based on your water data, budget, and household size.

MetricHonoluluWaikiki
Hardness80 PPM20 PPM
GPG4.71.2
TDS140 PPM35 PPM
PFAS3 ppt3 ppt
Lead1 ppb1 ppb
Chlorine1.3 mg/L1 mg/L
LevelModerately HardSlightly Hard

FAQ

Which has harder water, Honolulu or Waikiki?
Honolulu has harder water at 80 PPM compared to Waikiki at 20 PPM. That is a difference of 60 PPM.
Do I need a water softener if I move from Waikiki to Honolulu?
Probably not. At 80 PPM, the water is manageable without a softener for most homes.
Is Waikiki water safe to drink?
Waikiki water meets EPA safety standards. No contaminants exceed health guidelines in our data.