iSpring 6-stage alkaline RO three-year replacement set

Systems listed in our guide

F28K75 is associated with the following iSpring systems in our research. Open the model page to see every replacement associated with that system, then confirm with the manufacturer.

Filters and stages included

This listing covers the following components. Confirm the quantity, stage order, and part labels shown in the current manufacturer listing before ordering.

• Sediment pre-filters
• Carbon pre-filters
• 75-GPD RO membrane
• Inline post-carbon filters
• Alkaline remineralization filters

A complete kit does not mean every stage is due at the same time. Use the system manual’s schedule for each component.

Replacement schedule for F28K75

Three-year staged supply set; replace each component on its own schedule. Treat this only as general product guidance and follow the system manual. Water quality, usage, pressure, and sediment can change actual filter life.

Reverse-osmosis stages often expire on different schedules. Replacing this item does not necessarily mean the membrane, pre-filters, and post-filter are all due at the same time.

How to avoid ordering the wrong filter

• Confirm the system label includes the complete model, including every dash and suffix.
• Compare the installed part number with F28K75.
• Confirm the stage, membrane capacity, and connection style.
• Do not rely on cartridge color, dimensions, or product photography alone.

This larger supply set is intended for 6-stage alkaline RO configurations. Confirm the 75-GPD membrane capacity and stage count before ordering.

After installing the replacement

Follow the system manual, restore the water supply slowly, inspect every connection for leaks, and flush the new filter using the manufacturer’s specified volume before drinking the water.

If flow remains low, water tastes unusual, or a leak appears, shut off the supply and recheck the cartridge alignment, seals, tubing, and complete part number. Seek qualified help when needed.

How this entry was researched

We used the named manufacturer’s replacement information as the primary compatibility reference. Retailer descriptions are a purchasing aid, not our source of truth, and this research does not guarantee fit.