If you’re not familiar with National Safety Associates, it is a brand that once captured a large part of the filter consumer market in the 90’s. It has long discontinued its NSA product line. However, to this date, you can still find the NSA systems on sale online.
A loyal following of the NSA filtration system credits 50C model for its efficiency in removing contaminated particles from house tap water. There are also other features with this filter worth mentioning. Here, we will be taking on the ultimate NSA water filter review to find out more about what this filter offers households today.
You have 2 main choices when it comes to buying NSA filtering devices. The first is NSA 50C countertop filter. The second is NSA 100S.
NSA 50C

Manufacturer | NSA (USA) |
Capacity | 5,000 gallons(18,927 liters) |
Filter Type | NSA Bacteriostatic Water Treatment unit |
Filtration Stage/s | 5-stage |
Installation Type | Countertop |
Operating Pressure | Inquire from seller |
Maximum Flow Rate | 1 gallon/minute |
Maximum Temperature | Inquire from seller |
Weight | 5 pounds |
Dimensions | 11″ × 4″ |
Filtering Power

Its product description states that this filter can remove up to 20,000 different contaminants and even industrial compounds from contaminated water. This points to rust, dust, bacteria growth, germs, and other viruses that breed or settle in sink water.
Additionally, this bacteriostatic treatment device removes chlorine, odor, and taste from tap water. We should also mention that 50C filter will remove the smell and taste of sulfur from contaminated water. Even households that use well have commented that this sink filter works well in cleaning their water.
NSA 100S

Manufacturer | USA Filtration (USA) |
Capacity | 25,000 gallons (94,635 liters) |
Filter Type | Bacteriostatic Water Treatment |
Filtration Stage/s | 5-stage |
Installation Type | Undersink |
Operating Pressure | 20 Psi to 60 Psi. (1.4 bars to 4.1 bars) |
Maximum Flow Rate | 2 gallons/minute |
Maximum Temperature | 85°F (29.4°C) |
Weight | 7.28 pounds |
Dimensions | 14.92 x 6.46 x 5.47 inches |
Note that the 100S under sink filter described above is manufactured by USA Filtration to give filter owners the alternative option of replacing their NSA 100S unit since the brand has already discontinued further manufacturing of its filters in 2008.
NSA Systems Main Features

Makers of NSA 100S and 50C products ceased producing their 50C and 100S by 2008. Moreover, the company sold its list of customers and discontinued operating in the filter industry.
But even with the closure of the product lines, the company still has a huge volume of NSA 100S and other home water filtration units in stock. Members or distributors also have multiple inventories unsold in their homes or private shops. This is why NSA filtering units remain available for sale in many locations and even online.
Today, you can still find other alternatives to NSA filtration products. This includes H20 International filtration systems. Another option is USA Filtration. These two companies provide great replacement upgrades for NSA filters.
NSA 100S Replacement
Those looking for the best NSA 100S alternatives have some choices for replacement. Here we list 3 models with the features and benefits each one offers.
Product Details | iUS4-25K | Glacier GW1 | USA-100 |
---|---|---|---|
Manufacturer | Upflow Water | Glacier Water Systems | USA Filtration (USA) |
Capacity | 25,000 gallons (94,635 liters) | Inquire from seller | 25,000 gallons (94,635 liters) |
Filter Type | Bacteriostatic Treatment | The Bacteriostatic Treatment | Bacteriostatic Treatment |
Filtration Stage/s | 5-stage | 5-stage | The 5-stage |
Installation Type | Inline Under Sink | Under Sink | Under Sink |
Operating Pressure | 50 Psi | Inquire from seller | 20 Psi to 60 Psi. (1.4 bars to 4.1 bars) |
Maximum Flow Rate | 2 gallons/minute | 7 liters/minute | 2 gallons/minute |
Maximum Temperature | Inquire from seller | Inquire from seller | 85°F (29.4°C) |
Weight | 10.4 pounds | Inquire from seller | 7.28 pounds |
Dimensions | 16.5³ x 5.0³ | 38cm x 10.5cm | 14.92 x 6.46 x 5.47 inches |
Installing an NSA 50C
The NSA 50C screws to your faucet through the spout. Note that older models have short spouts. Your kitchen faucet should have a thread at the tip.
Sometimes, these units come with a strainer. If yours does, you will want to unscrew it first. Then, install the NSA 50C valve that comes with your purchased kit. You may place back the strainer after you’ve completed screwing the valve one.
Finally, connect the quick connect hose using the specific nut and compression sleeve. You will then have to lightly tighten the connection with some pliers. After that, your filter is ready for use.
At times you may need to throw out the first few filtered cups of sink water. So do this especially if there are some black particles that have come loose from the granular activated carbon and silver filter.
FAQs
How Long Do NSA 100S and 50C Units Last?
NSA filter system units are disposable. Each filter is fitted with granular activated carbon and silver, which serves to inhibit bacteria growth. Hence, it has a limited life. Further, the sink filter will degrade and it will consequently fail to absorb contaminants after it reaches its maximum use.
Here are some indicators for when it’s time for a new replacement filter:
- When the water quality is no longer as fresh-tasting and clear
- Once its water flow becomes limited or when it slows down
- Next, After you’ve used the sink filter for a maximum of two years
- If one has used it for 6 months to 1 year in a highly contaminated water area, and lastly,
- As soon as you’ve reached the filter maximum life of 3 years
We should also mention that NSA 50c filter is a completely sealed filtration device. There is no cartridge to replace. Hence, it is wholly disposable.
Why Does the Length of Use Vary Among NSA 50C Users?
The length of use varies with each household and location. Generally, one NSA 50C filter may last anywhere from 3 months to 3 years. Some sink water filter owners even reported being able to use this filtration device for 5 years. So what affects the length of use?
- Number of users in a household
- Quality of water in your area, and
- Frequency and volume of filtration
Does NSA 50C Filters Take out Fluoride?
Yes. Plain carbon filters may be inefficient in filtering out fluoride. But the NSA 50C filter uses granular activated carbon to clear your water of contaminants. And this includes filtering out fluoride in tap water.
Do the Connectors Come With the NSA 50 C?
Yes. Your purchase will include the accompanying quick connect hose. Users say the filter material is thick and durable, so it should last you a long while before you’d need to replace it. However, note that during initial use or at the installation of this filter, you may need to wipe it down. Do this first in order to remove the protective oil around it.
Does This Filter Have Available Replacements?
The NSA 50C quick-connect filter is a discontinued product. But an abundance of units remains available for sale. It is a disposable product since it is a sealed filtering device. So once you’ve used the filter to its maximum capacity, you need to buy a new unit to replace it.
Besides buying the same model as a replacement, you can also move up to an NSA 100S. USA Filtration also makes an available replacement for NSA 100S. The Water Marque filter for NSA 100S is also an option. Lastly, you may check replacement units from H20 Distributors. These NSA 100S replacement units and NSA 50C are all available for purchase online.
Final Thoughts
NSA filters 50C and NSA 100S have maintained a loyal customer base despite being discontinued for production. Units still sell online. And users give positive reviews on granular activated carbon efficiency in removing contaminants like chlorine, fluoride, bacteria growth, and filters other sediments from household tap water.
With a length of use that varies from 6 months to as long as 3 years, this drinking water filter is worth buying if the features and longevity appeal to you