Water filtration can feel overwhelming—but it doesn’t have to be. Whether you're dealing with sediment, strange odors, or just want better-tasting water, understanding the basics is the first step to making the right choice. In this article we will cover what water filtration is and the best way to select a filtration system for your needs.
Water filtration is the process of removing unwanted particulate and undesirable taste and odors. It is important to understand that traditional water filters are not water treatment systems. You must always get your water properly tested before determining which filtration system to use.
WARNING: Do not use with water that is microbiologically unsafe or of unknown quality without adequate disinfection before or after the filter. Traditional filters improve appearance, taste, and odor—but they do not make unsafe water safe.
Filtration systems typically remove:
Selecting a water filter correctly is critical. The most common mistake is choosing a filter housing first and then trying to fit a cartridge into it. This often leads to:
When it comes to traditional sediment filter housings and cartridges, it is better to err on the side of too large than too small. Here are the Five Required Steps:
Before selecting any filtration system:
Testing helps determine what type of cartridge is required and ensures proper system sizing.
The type of cartridge needed depends on the specific water issue:
► Sediment / Appearance Issues
Use Sediment cartridges such as:
► Taste Issues
Use Activated Carbon cartridges:
► Odor Issues
Also use Activated Carbon cartridges (CB, GAC, CW).
Desired Flow Rate is the volume of water in gallons per minute (GPM) that you want to have available when multiple faucets or appliances are in use. To determine the flow requirement needed for your filter, rather than basing this need on the gallons per day usage of your home, you would need to calculate your peak flow demand in gallons per minute (GPM). Below is a guide on the GPM range of common appliances and fixtures.
Typical Fixture GPM Ranges:
Consider:
Choose a cartridge with a flow capacity significantly higher than your required GPM.
Rule of Thumb:
Why Oversize?
Published flow rates are based on clean cartridges. As sediment accumulates pressure drops and flow decreases.
If you select a filter cartridge at the minimum desired flow rate, the cartridge will quickly fall below acceptable performance and require premature replacement resulting in increased filtration costs.Ideally, cartridges should last 4–6 months, with changeout at six months to prevent bacterial buildup.
Outside Diameter:
Length (available in both Standard and Giant size Outside Diameter):
Notes:
The housing must accommodate the correctly sized cartridge.
Housing Types:
Material Options:
Bowl Options:
Other than the filter bowl lifespan, temperature rating, and UV limitations, the choice between blue and clear filter bowls often come down to customer preference. Some customers like to see what is going on inside their filter bowl, other customers prefer not too.
Giant housings offer multiple inlet/outlet connection sizes.
To help decide between these, consider Flow Velocity. It is recommended to size piping to maintain a water velocity of 5 ft/second (1.524 LPM). Five feet per second is a threshold that is widely accepted by engineers and designers because beyond this velocity, the friction losses, danger of water hammer, and pipe movement due to water momentum changes are deemed to be too high.
When higher flow capacity is required, it may be necessary to install 2 filter housings in parallel.
In conclusion, choosing the right water filtration system doesn’t have to be complicated—it just requires a thoughtful, informed approach. By understanding what filtration can and cannot do, starting with proper water testing, and carefully matching the right cartridge, flow rate, and sizing to your specific needs, you can avoid common mistakes and unnecessary costs. Taking the time to size your system correctly and prioritize performance over convenience ensures not only better water quality but also longer-lasting, more efficient filtration. Ultimately, a well-chosen system provides peace of mind—delivering cleaner, better-tasting water for your home while protecting your investment in the long run.
Head over to Boshart's Knowledge Base: technical product information, guidelines, and more.