Water hardness in Guía de Isora
10 °fH moderately hard
Tap water in Guía de Isora is moderately hard: 10 °fH (100 mg/L · 5.8 gpg · 5.6 °dH).
Source: SINAC, Ministerio de Sanidad — Información de un abastecimiento, municipio 38019 (2026-08) · data checked 2026-10-19
Range across supply zones: 35–312 mg/L.
SINAC data from the Ministry of Health for August 2026 put Guía de Isora at 100 mg/L CaCO₃, with readings from 35 to 312 mg/L, so it varies a lot with the supply point and the blend at the time. In the western Canary Islands water comes mostly from galleries and wells in volcanic rock, with desalination in some areas; hardness changes with the blend. Limescale is hardly noticeable at this level, and most households do not need a softener.
Fuentes españolas usan °fH (grados hidrotimétricos franceses) o mg/L CaCO₃.
Water data
| Total hardness | 10 °fH |
|---|
How Guía de Isora compares
- Tap water in Guía de Isora is 50 % softer than the median of the 4988 cities we track in Spain (20.1 °fH).
- By hardness it ranks 3571 of 4988 in Spain (1 = hardest); 28 % of these cities have softer water.
- In Santa Cruz de Tenerife it is number 25 of 48 cities; the regional median is 10 °fH.
- Nearest city with clearly softer water: Adeje, 9 km away (6.5 °fH).
- Nearest city with clearly harder water: Santiago del Teide, 9 km away (17.9 °fH).
Ranking of the hardest and softest water in Spain →
What it means at home
- Visible kettle scale every few weeks; vinegar or citric acid is enough.
- Water heater and washing machine: some long-term scale; a scale inhibitor slows it.
- Dishwasher: medium salt setting.
- Softener optional; pays off mainly with a gas boiler or tankless heater.
How much salt will you use for softening?
Optional. A scale inhibitor or a small softener protects the heater; soap savings are modest.
Descale a coffee machine or kettle about every 3 months (typical manufacturer guidance for this hardness).
Estimates for planning, not a quote. Check your appliance manual for exact settings.
Dishwasher setting in Guía de Isora
| Brand | Setting for this water |
|---|---|
| Bosch | H00 |
| Miele | 6 °dH |
| AEG / Electrolux | 2 |
| Beko | 2nd |
| Hoover | S1 |
| LG | H1 |
From each brand's manual for the model family named in the source; your model may differ, so check its manual. All brands and how to change the setting →
FAQ
Is Guía de Isora water hard or soft?
It is moderately hard: 100 mg/L as CaCO₃ (5.8 gpg, 5.6 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Guía de Isora safe to drink?
Hardness is not a health issue; it is about limescale, taste and appliances. Mains water must meet national drinking-water standards. Fuentes españolas usan °fH (grados hidrotimétricos franceses) o mg/L CaCO₃.
How many grains per gallon is Guía de Isora water?
5.8 gpg, equal to 5.6 °dH, 10 °fH or 100 mg/L calcium carbonate.
What dishwasher salt setting should I use in Guía de Isora?
For 100 mg/L (5.6 °dH) check your manufacturer's table: level 2–3.
Do I need a water softener in Guía de Isora?
Not essential; a scale inhibitor protects the heater cheaply.
Source
Source: SINAC, Ministerio de Sanidad — Información de un abastecimiento, municipio 38019 (2026-08). Method: own measurement. SINAC, Ministerio de Sanidad — Información de un abastecimiento, municipio 38019 · Outdated figure? Tell us