Common Water Contaminants: What's in Your Water and How to Remove Them
Not all water filters remove the same things. Here's a breakdown of the most common contaminants found in tap water, what they do, and which RKIN systems remove them.
Chlorine & Chloramines
What they are: Disinfectants added by water utilities to kill bacteria. Safe at low levels, but they cause that "pool water" taste and smell, dry out skin and hair, and can form harmful byproducts over time.
How to remove them: Activated carbon filtration removes 99%+ of chlorine and chloramines. Found in:
- OnliSoft Pro (whole house)
- ZIP (countertop)
- U1 (countertop)
Lead
What it is: A toxic heavy metal that leaches from old pipes and solder joints. There is no safe level of lead exposure, especially for children.
How to remove it: Reverse osmosis (RO) systems certified to NSF/ANSI 58 are the gold standard for lead removal:
PFAS / PFOA / PFOS ("Forever Chemicals")
What they are: Man-made chemicals used in nonstick coatings, food packaging, and firefighting foam. They don't break down in the environment or your body — that's why they're called "forever chemicals." Found in water supplies across the country, and a growing public health concern.
How to remove them: RO membranes are highly effective at rejecting PFAS compounds. The ZIP is certified for PFAS removal.
Fluoride
What it is: Added to most municipal water supplies for dental health. Some people prefer to remove it for personal or health reasons.
How to remove it: Standard carbon filters do NOT remove fluoride. You need reverse osmosis:
Hardness (Calcium & Magnesium)
What it is: Dissolved minerals that cause scale buildup in pipes, water heaters, and appliances. Hard water also leaves spots on dishes and makes soap less effective.
How to treat it:
- Salt-free conditioning: OnliSoft — converts hardness into crystals that won't form scale. No salt, no wastewater, no slippery feeling.
- Salt-based removal: Traditional water softener — physically removes calcium and magnesium through ion exchange. Best for very hard water (25+ GPG).
Sediment, Rust & Sand
What they are: Physical particles from aging pipes, well casings, or municipal water mains. Visible as cloudy water, grit, or orange/brown discoloration.
How to remove them: Sediment pre-filters are included on all RKIN whole-house systems and RO systems. They catch particles before they reach the finer filters.
VOCs, Pesticides & Herbicides
What they are: Volatile organic compounds and agricultural chemicals that can enter water supplies through runoff and industrial contamination.
How to remove them: Carbon block pre-filters are highly effective against VOCs. Included in RKIN RO systems (ZIP, U1) and the OnliSoft Pro's carbon stage.
TDS (Total Dissolved Solids)
What it is: A measure of everything dissolved in your water — minerals, salts, metals, organic matter. High TDS doesn't always mean unsafe water, but it affects taste.
How to reduce it: RO systems reduce TDS by 95–99%. If you're testing your water with a TDS meter, this is the number you'll see drop dramatically after filtration.
What We Recommend
On city water? Start with an OnliSoft Pro for whole-house protection (hardness + chlorine + sediment), then add a countertop RO like the ZIP or U1 for drinking water.
On well water? Every well is different. Contact us for a free consultation — we'll review your water test results and recommend the right setup for your specific situation.
Get a Free Consultation
Not sure which system you need? Our water specialists can help you figure out exactly what's in your water and what to do about it.
- Phone: 1-800-803-4551
- Online: rkin.com/pages/contact