Osmosis is when water passes through a membrane (a sheetlike boundary) and other materials cannot pass through or can only pass through in lower amounts. Osmosis happens in all living things naturally, because all life needs water. When water is separated by a membrane, pressure is created by the amount of foreign materials in the water. The pressure will push water from the side of the membrane with less foreign materials until there is a balance between water and foreign particles is equal on both sides.
With some clever science and engineering, osmosis can be made to work for us. We just add pressure, from your home’s water pressure, to the side with more foreign material. The extra pressure can stop or reverse this flow. This means that water will now only flow away from the foreign material. This is Reverse Osmosis.
In Reverse Osmosis we apply extra pressure to the water to push it through thousands and thousands of membrane layers. The extra pressure stops foreign materials from drawing water to them. The result is these foreign materials are left behind and the only thing that can come through the membrane layers is pure water.
The Reverse Osmosis Membrane is only one stage of our RO Systems; it’s the 4th stage. The 1st stage is a Sediment filter which helps filter things like dirt, sand, dust, and rust. The 2nd and 3rd stages are Carbon Filters which filter things like chlorine, volatile organic chemicals, and odor-causing compounds.
These early stages help extend the life of the Reverse Osmosis Membrane by taking care of many larger coarse contaminants which could damage it. But they do not deal well with Total Dissolved Solids (TDS) which are the most difficult to remove. Up to 99.99% of TDS are removed by the RO Membrane as well as other difficult contaminants like lead, arsenic, chromium, and radium. The Membrane is where most of the purification takes place.
The 5th stage is a granular-activated carbon filter which does a final pass on your water right before you drink it. This last stage is focused on removing any possible taste or odor in your water. It’s the combination of these stages that’s helped countless customers have water purer than bottled water straight from their faucet.
Total Dissolved Solids (TDS) are all organic and inorganic contaminants that have been dissolved into water. These contaminants are gathered from everything water comes into contact with before it finds its way to you. Common elements of TDS are Iron, Sulfate, and Chloride.
Reverse Osmosis reduces a huge variety of Total Dissolved Solids in water.
We have charted out some common TDS contaminants and what percent of reduction you can generally expect below.
These numbers are based on tap water tested in Southern California. The exact results may vary depending on the water quality in your area.
Contaminate comparison chart: Reverse Osmosis vs Pitchers and Faucet Mounted Filters.
NSF's rating for reduction of Giardia Cysts and Cryptosporidium is 1 micron, and the Thin Film Membrane (TFM) filters down to 1/10,000th of a micron. That is 10,000 times smaller than these parasites. These contaminants are too large to pass through the TFM membrane. Although, a health claim cannot be made because of intangibles such as regular maintenance.
Impurities removed by the RO System are washed down the drain. Unlike other filters, the Reverse Osmosis membrane is self-cleaning. As water flows through the RO membrane, it is divided into two streams. One stream is pushed through the membrane by your water pressure. The second stream flows to the drain carrying dissolved pollutants, rejected salts, and contaminants. This means very little debris accumulates on your membrane allowing it to last for about a full year of use.
| Contaminants | Avg Influent Conc. (mg/L) | Avg Effluent Conc. (mg/L) | Avg % Reduction | Max Effluent Conc. (mg/L) |
|---|---|---|---|---|
| Arsenic | 0.28 | 0.0035 | 98.7 | 0.0052 |
| Barium | 10.2 | 0.207 | 97.9 | 0.3 |
| Cadmium | 0.036 | 0.0005 | 98.6 | 0.0007 |
| Chromium (Hexavalent) | 0.15 | 0.013 | 91.3 | 0.03 |
| Chromium (Trivalent) | 0.17 | 0.01 | 94.1 | 0.01 |
| Copper | 3.1 | 0.03 | 99.0 | 0.04 |
| Cysts | 149357 #/ml | 5 #/ml | 99.99 | 17 #/ml |
| Turbidity | 10.2 | 0.26 | 97.5 | 0.83 |
| Fluoride | 8.0 | 0.5 | 93.9 | 0.7 |
| Lead | 0.15 | 0.002 | 98.6 | 0.003 |
| Perchlorate | 0.10 | 0.003 | 96.5 | 0.005 |
| Radium 226/228 | 25 pCi/l | 5 pCi/l | 80.0 | 5 pCi/l |
| Selenium | 0.10 | 0.10 | 92.0 | 0.011 |
| TDS | 790 | 24 | 97.0 | 800 |
| Contaminates | Reverse Osmosis | Standard Filtration Products | Faucet Mount and Pitchers |
|---|---|---|---|
| Arsenic (Pentavalent) | ✔️ | ✖️ | ✖️ |
| Perchlorate | ✔️ | ✖️ | ✖️ |
| Barium Reduction | ✔️ | ✖️ | ✖️ |
| Cadmium Reduction | ✔️ | ✖️ | ✖️ |
| Copper Reduction | ✔️ | ✖️ | ✖️ |
| Cyst Reduction | ✔️ | ✔️ | ✔️(Faucet) |
| Chromium (Hexavalent) Reduction | ✔️ | ✖️ | ✖️ |
| Fluoride Reduction | ✔️ | ✖️ | ✖️ |
| Lead Reduction | ✔️ | ✔️ | ✔️ |
| Radium 226/228 Reduction | ✔️ | ✖️ | ✖️ |
| Selenium Reduction | ✔️ | ✖️ | ✖️ |
| TDS Reduction | ✔️ | ✖️ | ✖️ |
| Chromium (Trivalent) Reduction | ✔️ | ✖️ | ✖️ |
| Turbidity Reduction | ✔️ | ✔️ | ✔️ |
| Chlorine (taste and odor only) | ✔️ | ✔️ | ✔️ |
| Results | 15 Reductions out of 15 | 4 Reductions out of 15 | 4 Reductions out of 15 |
Your home’s water pressure plays a key role in how well your Reverse Osmosis (RO) system performs. Pressure helps force water through the RO membrane and flush out unwanted contaminants. Ideally, water pressure should be around 60 PSI. If your pressure drops below 40 PSI, the system might operate inefficiently or damage the membrane over time. In such cases, we recommend installing a booster pump. If your pressure is too high, a pressure regulator can help maintain a safe range.
Need help choosing the right equipment? Call us at 317-934-8867 or visit zenithpuresolutions.com
Excessive iron in water can clog the RO membrane since it's not capable of removing iron on its own. If you have iron levels below 1 PPM (parts per million), it’s generally safe. Up to 2 PPM can be treated with a water softener before it reaches your RO unit.
Note: “Clear water iron” leaves no stain, but “red water iron” can leave rusty marks in sinks and toilets — and should be treated beforehand.
Water from your RO system is noticeably cleaner in both taste and appearance. It’s perfect for drinking, cooking, and even making coffee or tea. Ice cubes from RO water are typically clearer, harder, and last longer than regular ice.
Put tap water ice cubes and RO ice cubes in two identical glasses. You'll likely see the RO cubes melt slower — and you won’t find sediment at the bottom afterward.
You can test the performance of your RO system with a conductivity meter, which detects Total Dissolved Solids (TDS) in your water. A lower reading indicates cleaner water. At Zenith, we also offer testing kits if you'd like us to help evaluate your system and let you know when to replace your membrane.
With proper care and normal water conditions, your RO system can last 5–10 years. The water tank typically lasts 3–5 years before needing replacement. Regular filter changes are essential for long-term durability.
Most Zenith RO systems fit neatly under a standard kitchen sink. The main filtration unit measures approximately 15.75\" x 16.25\" x 5.25\", and the storage tank is about 11\" x 16\" x 11\".
Our systems operate best with 40–80 PSI. If your water pressure is outside this range, we offer both booster pumps and pressure regulators to help adjust it safely.
Not sure what you need? Contact our support team — we're happy to help you determine if the system is right for your space and plumbing setup.
A standard RO tank has a capacity of up to 3.2 gallons, but most users will see about 2 to 2.5 gallons available for use. Water pressure impacts how much water the tank actually holds — lower pressure means less storage volume.
Water softeners are not designed to purify your drinking water. Their primary purpose is to remove hardness-causing minerals like calcium and magnesium, which helps protect your home’s plumbing and appliances. However, softeners do not remove other impurities like chemicals, heavy metals, or microorganisms — which is why they’re not a complete solution for drinking water needs.
Not at all — in fact, it’s quite the opposite. A water softener can actually extend the lifespan of your Reverse Osmosis system. By replacing hard minerals like calcium and magnesium with sodium, the water becomes much easier on your RO membrane. The small amount of sodium added is easily filtered out — RO membranes typically remove over 98% of it.
Yes, an RO system naturally reduces water hardness to some degree. However, if your water is classified as very hard (typically above 7 grains per gallon), the membrane will wear out much faster. To prevent this and get the best performance, we recommend pre-treating your water with a softener before it enters the RO system.
If you live in an area with hard water, the ideal solution is to install a water softener at your home’s point of entry. This way, all incoming water is treated for hardness. Then, use a Reverse Osmosis system at the point of use — usually under the kitchen sink — to ensure clean, purified drinking water. This combo protects your pipes and appliances while giving you crisp, clean water straight from the tap.
Need help designing your setup? Contact Zenith Pure Solutions — we’ll help you find the perfect configuration based on your water quality and home layout.
Yes, a portion of the water processed by a Reverse Osmosis (RO) system is discharged as wastewater. This water contains the contaminants that the system has removed — particles too small to be captured by standard filters. Instead of building up inside the system, these impurities are flushed away through a drain line. The amount of wastewater generated depends on the quality of your source water.
Most RO systems use about three gallons of water for every gallon of purified water they produce. This 3:1 ratio may vary depending on your home’s water pressure, temperature, and overall water quality.
Yes — while you should never drink it, RO wastewater can be reused for certain non-potable applications. For example, many homeowners redirect this water for landscape irrigation, toilet flushing, or even to clean outdoor areas. Because it contains higher Total Dissolved Solids (TDS) than tap water, it's ideal for tasks that don't require purity.
Helpful Tip: If you’d like to install a simple wastewater recovery solution, Zenith Pure Solutions can help you explore smart plumbing options to make your system even more efficient.
To keep your Reverse Osmosis system running at peak performance, we recommend replacing the first three filter stages — sediment and carbon pre-filters — every six months. These filters handle the bulk of dirt, chlorine, and chemicals before they reach your RO membrane. Regular replacements help prevent clogging and extend the life of your system.
Keep in mind that local water conditions may affect how frequently you need to change your filters. If your water has more sediment or chemical content, more frequent changes may be needed.
No — not with Zenith systems. Our RO units include an advanced inline flow restrictor that is designed to last. Unlike older models, our restrictors can be cleaned rather than replaced. When you change your RO membrane, just check that the flow restrictor is still clear and functioning — there’s usually no need to buy a new one.
Need help with filter replacements? Reach out to Zenith Pure Solutions — we’ll help you choose the right filters and provide maintenance tips for long-term performance.
Absolutely! Zenith RO systems are fully customizable. You can enhance your system by adding optional filters like:
If you're interested in upgrading, visit our Accessories & Add-Ons page or contact our team for guidance.
Yes, you can connect your Zenith RO system to most refrigerators or ice makers. You may need a refrigerator hookup kit, and depending on the distance, a delivery pump or extra tank might be required to maintain consistent flow. Reach out to us for help customizing your setup.
You sure can! To double your output, you’ll need a higher-capacity membrane (100 GPD) and a compatible flow restrictor. Our team can help ensure your system is matched with the correct parts and operates efficiently at the higher flow rate.
Need help upgrading? Call us at 317-934-8867 or email us at sales@zenithpuresolutions.com. We’re here to help you make the most of your filtration system.
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Zenith Pure Solutions
6951 East 30th Street, Ste B,
Indianapolis, IN, USA