Summary:

• You need access to clean water for drinking, bathing, washing clothes, and other daily activities. Water filtration systems help by removing common contaminants—like sediment, hard water minerals, bacteria, and lead.
• Whole-house water filters, reverse osmosis filters, carbon filters, and water softeners each treat different concerns. Understanding these differences can help you make the right choice for your home.
• Before you make a purchase, have your water tested. Local utility providers like Mid-Peninsula and EBMUD offer free testing, or you can test at home with a kit.
• You’ll need to know your daily water use in gallons to find the right product. Multiply 80 to 100 gallons per day per person—but be aware this doesn’t include pools. 
• Once you nail down a budget and start shopping, look for the National Sanitation Foundation (NSF) logo on every product. Leave installation to a licensed plumber.

California goes to great lengths to treat its water supply, but contaminants can still build up. Some of the most common examples we see in the Bay area include hard water, chlorine, iron, manganese, and lead from older pipes.

While you can’t control your well or municipal water, you can make upgrades at home that remove potentially hazardous contaminants. The right water softener or filtration system can help improve the quality of your water—or even prevent you from getting sick!

In this guide, we’ll explain why being careful about your water matters, how different systems work, and how to choose the right water treatment solution for your home.

For more help, reach out to Caccia Plumbing at (650) 294-8551 or send us a message!

Why You Need Water Filtration

Water filtration protects your home and health by removing contaminants either before they enter your home or at designated points in your plumbing system. The EPA classifies drinking water contaminants into four main categories:

1. Physical contaminants include sediment, manganese, iron, organic material, and debris.
2. Chemical contaminants include salts, metals, bleach, pesticides, and chemicals.
3. Biological contaminants include bacteria, viruses, protozoa, and parasites.
4. Radiological contaminants include uranium, radon, and cesium.

Very low or trace contaminants might be harmless or only affect the smell and taste of your water. When levels get too high, they can make you seriously sick or damage your plumbing.

See our water filter solutions

1. Whole-House Water Filtration Systems

Whole-house water filters sit on your main water line and treat all water entering your home. These systems typically use multiple stages of carbon and sediment filtration to remove chemicals, metals, and odors.

Pros:

• Completely filters all water that comes into your home.
• Very effective at removing chlorine, sediment, and heavy metals.
• Improves water quality for bathing, drinking, and cleaning.

Cons:

• Costs more than other water filtration systems.
• Not DIY-friendly—must be installed by a licensed plumber. 
• Needs regular maintenance to stay in good working order.

2. Reverse Osmosis (RO) Systems

RO systems are typically installed under sinks or at specific faucets. They work by forcing water through a semipermeable membrane, which attracts and removes dissolved solids and microscopic contaminants.

Pros:

• Creates high-purity water that’s ideal for drinking, cooking, and making baby formula.
• Removes microscopic particles and dissolved substances that standard filters don’t catch.
• Often includes pre-filters and post-filters (e.g, carbon) for even better results.

Cons:

• Wastes up to 3 gallons of water for every gallon filtered.
• Very slow compared to some other systems (like carbon or whole-home).
• Removes beneficial minerals, so you may need to remineralize your water.

3. Carbon Filters

Activated carbon filters absorb impurities, improve taste and odor, and remove chemical contaminants like chlorine and VOCs. They can be installed at specific taps or the main line.

Pros:

• Very affordable compared to other water filtration systems.
• Effectively removes chlorine, VOCs, benzene, and some heavy metals.
• Greatly improves the taste and appearance of water.

Cons:

• Doesn’t remove all contaminants, including bacteria, nitrates, and dissolved solids.
• Filters must be replaced often for maximum results (sometimes every month).
• A poor choice if you’re looking for protection from infectious microbes.

4. Water Softeners

Water softeners are usually installed on your main water line. Salt or resin beads inside the filter attract hard water minerals, like iron, and send them down the drain. The cleaned water proceeds into your home.

Pros:

• Extremely helpful for areas with very hard water or high mineral levels.
• Reduces hard water scale and lowers the risk for damaged appliances.
• Makes soap lather better and improves how skin and hair feel after washing.

Cons:

• Won’t remove chemicals like chlorine or some heavy metals.
• The salt or resin inside needs to be replaced every few years.
• Salt softeners may not be suitable for people on low-sodium diets.

See our water softener solutions

Specialized Filters and How They’re Different

Specialized systems target specific contaminants or issues. You can buy them separately, but they’re often used in combination with whole-house systems for tailored protection.

The most common examples include:

• UV (Ultraviolet) Disinfection destroys bacteria, viruses, and other pathogens by passing water through ultraviolet light.
• KDF (Kinetic Degradation Fluxion) removes chlorine, heavy metals like lead and mercury, bacteria, and algae by passing water through copper-zinc alloy granules.
• Oxidizing Filters remove iron, manganese, and hydrogen sulfide by converting dissolved contaminants into solid particles, then filtering them out.
• Air Stripping/Aeration Units reduce VOCs and volatile gases like radon or hydrogen sulfide by exposing water to air inside a chamber.
• Anion Exchange Units (AEU) remove nitrates, arsenic, or tannins. Like water softeners, they pass water through a bed of resin, but the type of resin is different.

Pros:

• The best option for homeowners who have unique or special filtration needs.
• UV (Ultraviolet) lowers drinking water risks for people who are immunocompromised.
• KDF is best for reducing chlorine, lead, mercury, and algae growth.
• Oxidizing filters help prevent rust stains and rotten egg odor.
• Air stripping is one of the best options for VOCs and radon.
• Anion exchange units effectively remove nitrate, arsenic, and tannin.

Cons:

• Costs may be higher if you need to buy, install, and maintain multiple systems.
• All require regular maintenance and care to continue filtering water effectively.
• Won’t cover other filtration needs outside of their own specialization.
• Can be costly compared to other water filtration systems.

Related: How to Prevent Sink, Shower, and Rust Stains

Comparing Water Filtration Systems Side-by-Side

Note: Prices vary based on complexity and seller.

Questions to Ask Before You Buy a Water Filtration System

When looking for a water filtration system for your house, the first factor you should consider is the type of water you have. If you have that information already on hand, you’re ahead of the game. If you don’t, testing will confirm exactly what you’re up against.

1. What’s in My Water?

Determining what’s in your water is the first step. In the Bay Area, local utilities like EBMUD and Mid-Peninsula will either provide free or low-cost water testing or cover the cost of lab testing for local residents.

Utilities like these also typically provide an updated copy of their most recent water supply testing results online. The report should list the concentration of any pollutants or contaminants and the EPA-mandated Maximum Contaminant Levels (MCLs). 

If you’d prefer to test at home, you can buy affordable testing kits at most hardware stores, and they’re very affordable. The only catch is that they can’t always identify unique contaminants—you’ll need lab testing for that. 

2. How Much Water Do I Use?

Filtration Rate (FR) tells you how many gallons a system can handle each day. You should compare this to the amount of water you use each day before you start shopping.

Start by thinking about how much water your household uses:

• For estimation purposes, a typical person uses 80 to 100 gallons per day.
• This figure includes showers, laundry, dishes, and drinking, but not pools.
• Multiply that by the number of people in your home to get a rough estimate.

If you have a water feature, irrigation for your lawn or garden, or a pool, the amount of water you use may be much higher. This virtual water use quiz can help you calculate your use. 

Once you have the number, keep it with you when you’re shopping. Make sure the system you invest in is slightly more than capable of handling it—with a little wiggle room.  

3. What’s My Budget?

Most homeowners don’t want to spend any more on water filtration than they have to, and that’s totally reasonable. Try to nail down what you’re willing to spend in advance, but keep in mind that water quality has the potential to cause serious harm.

If your issue is related to health concerns or substances that can damage your plumbing and appliances, it makes sense to spend a little bit more. You’ll get more comprehensive protection without risking your health or plumbing in the process.

If your issue is harmless but aesthetic in nature, like slight discoloration, temporary odd smells, or a slightly metallic taste, a simpler, more affordable system may be enough.

4. Are All Systems Equally Effective?

No. The National Sanitation Foundation (NSF) is a non-profit organization that analyzes and certifies food, water, and consumer items to enhance public health. Look for the NSF International mark before you buy—it means the system is certified to do what it claims.

5. Do I Need Professional Installation?

In general, we only recommend attempting a DIY installation on temporary filtration systems, like carbon tap filters or KDF shower head filters. These are very easy to install, and there’s a fairly low risk of expensive problems if something goes wrong.

For whole-home systems and other permanently installed filters, we strongly recommend leaving the job to a plumber. These systems often need to be connected directly to your main water line, which involves:

• Shutting off your water supply
• Cutting into pipes
• Installing bypass valves
• Installing pressure regulators. 

Our licensed plumbers have the skills to install these systems safely, up to code, and without any surprise leaks or floods—which means fewer leaks or emergencies later on.

Protect Your Water Quality With Caccia Home Services

At Caccia Home Services, we don’t just work in the Bay Area—we live here, raise our kids here, and in some cases, even drink the same water. That’s why we’re so passionate about helping our neighbors in San Mateo and the rest of the peninsula access clean water.

Send us a message for professional help installing a high-quality filtration system that gives you peace of mind and preserves your plumbing in the process. Because it’s not just about clear water—it’s about keeping you safe!

Frequently Asked Questions about Water Filtration

Are Contaminants Always Dangerous?

No. The mere presence of a contaminant doesn’t automatically mean the water is unsafe to use or drink. Some, like lead or arsenic, are harmful outright, while others cause no harm at all or only affect the taste, color, or smell of your water.

The Safe Drinking Water Act (SDWA) gives the EPA the right to set limits and guidelines and enforce them at the federal level, but they aren’t foolproof.

How do I know when my filter needs to be replaced?

Check the instructions in the user guide it came with—or on the box, if you’re shopping. 

In general, most filters have a rated lifespan based on gallons filtered or time (like 3 to 6 months). If your water pressure suddenly dips or you start to notice sediment, a bad smell, a weird taste, or strange colors, you may need to change it out more regularly. 

What’s the difference between filtration and purification?

Filtration removes unwanted particles and some chemicals from water—like sediment, chlorine, or metals—using physical barriers or media. Purification goes a step further and often includes methods like reverse osmosis or UV light to kill or remove viruses, bacteria, and dissolved contaminants. 

Can I use one system to treat both city and well water?

Not necessarily. If you’re in an area like Woodside, Portola Valley, or Montara City and have both well and city water, you probably have different needs. On city water, the priority is usually to treat chlorine and other pipe-related contaminants. For well water, filtering out bacteria and softening hard water is often more important.

Nailing down the specifics can be challenging in circumstances like these, so we don’t recommend shopping on your own. Give us a call, and we’ll help you find the best option!