Question 1

What does a reverse osmosis system remove from Denver water?

Accepted Answer

A 5-stage RO system removes 95-99% of dissolved solids (TDS), including chloramines (which Denver Water uses), nitrates, fluoride, lead, arsenic, chromium, and trace pharmaceuticals. Denver's tap water has a TDS of 280-340 ppm — an RO system reduces this to under 30 ppm.

Question 2

Do I need both a water softener and reverse osmosis?

Accepted Answer

They serve different purposes. A water softener protects your whole house from scale damage. An RO system provides high-quality drinking water. Many Denver homeowners use both: a softener on the whole house and RO under the kitchen sink for drinking and cooking.

Question 3

How much does an RO system cost in Denver?

Accepted Answer

Under-sink systems: $200-$600 equipment + $150-$300 installation = $350-$900 total. Annual filter replacement runs $50-$150. Whole-house RO: $2,000-$5,000 equipment + $1,000-$1,500 installation — typically overkill for Denver's safe municipal water.

Question 4

How much water does an RO system waste?

Accepted Answer

Traditional RO systems waste 3-4 gallons of water for every gallon produced. Newer tankless/high-efficiency models waste only 1:1 or less. For Denver homeowners concerned about water usage, look for models with a permeate pump or closed-loop design.

Question 5

How often do RO filters need replacing?

Accepted Answer

Pre-filters (sediment, carbon): every 6-12 months. RO membrane: every 2-3 years. Post-filter (polishing carbon): every 6-12 months. Denver's relatively clean municipal water means filters typically last toward the longer end of these ranges.

Question 6

Does RO remove fluoride?

Accepted Answer

Yes, RO membranes remove approximately 85-95% of fluoride. Denver Water adds fluoride to 0.7 mg/L for dental health. If you prefer to keep fluoride in your drinking water, RO is not ideal for you without remineralization.

Question 7

Will hard water damage my RO membrane?

Accepted Answer

Yes, hard water can clog and damage RO membranes faster. Denver's 7.8 GPG hardness will reduce membrane life. If you have a whole-house water softener already, install the RO after it. If not, use the RO as-is but expect to replace the membrane every 18-24 months instead of 2-3 years.

Question 8

How long does it take to fill the RO storage tank?

Accepted Answer

Standard tanks fill in 2-4 hours from empty. A full tank (3-5 gallons) is enough for typical daily drinking/cooking needs. Tankless systems produce water on demand without waiting.

Question 9

Is RO water healthy to drink?

Accepted Answer

Yes, RO water is safe and healthy. Some people add a remineralization filter (5th or 6th stage) to add back beneficial minerals for taste. RO water tends to taste very clean and flat compared to mineral water.

Question 10

Can I use RO water in a fish tank or plant watering?

Accepted Answer

RO water (near-zero TDS) is excellent for sensitive fish and plants. Fish like discus thrive in ultra-pure RO water. For most houseplants, RO water is fine, though tropical plants may need added fertilizer since RO removes all minerals.

Reverse Osmosis FAQ