Replacement Filters for the Watts W-415 (4-Stage) Reverse Osmosis System
Watts · 4-Stage Reverse Osmosis
Replacement Filters for the Watts W-415 (4-Stage) Reverse Osmosis System
Every filter your system needs — stage by stage — led by the IPW house-brand set that costs less than the OEM parts.
Also sold as: Watts W-415 · W-415 · Watts 4 stage RO
✓ Best value — replace everything at once
W-415 IPW set + 3/8" QC inline — best value
$39.99
5µm sediment + 5µm carbon block (10" × 2.5") + 50 GPD membrane + 10" inline GAC with 3/8" quick-connects. Fits the Watts W-415.
🛒 Add the complete set to cartFilters by stage
Buy the whole set above, or replace stages individually below.
4
Inline post-carbon polish
10" × 2" coconut GAC · 3/8" quick-connect
ICF-10Q38 — inline GAC, 3/8" QC — $12.99
When to replace
🪣 Sediment & carbon: every 6–12 months🥤 Inline post-filter: every 6–12 months💧 RO membrane: every 2–3 years
✓ Fits the Watts W-415: 10" × 2.5" pre-filters, 50 GPD membrane and 10" × 2" inline post-filter (3/8" QC) — not sure? call (714) 541-6600.
Not sure this is your system? Use the Isopure Water Filter Finder → Match by system name, by the part number printed on your current filter, or by snapping a photo.
Watts W-415 filter FAQ
What filters does the Watts W-415 use?
Four: a 5 micron 10" × 2.5" sediment filter, a 5 micron 10" × 2.5" carbon block, a 50 GPD thin-film RO membrane and a 10" × 2" inline GAC post-filter. The W-415 set has all four.
How often should I change the W-415 filters?
Replace the sediment, carbon block and inline post-filter every 6 to 12 months. Do not run them longer than 12 months. The membrane usually lasts 2 to 3 years, depending on your water.
Is the Watts W-415 still made?
No. Watts lists the W-415 as discontinued and replaced by the W-525. Filters for the W-415 are still available here. See the Watts W-525 page if you have the newer model.
What size fittings does the W-415 inline post-filter use?
The W-415 set ships with a 3/8" quick-connect inline post-filter. Check the tubing on your system. If it is 1/4", call (714) 541-6600 and we will match the right inline filter.
All replacement filters by system · Watts RO & OneFlow replacement filters · Watts W-525 · Watts Premier 560032
Compatibility reference only. Photos of complete systems shown on this page are provided to help you identify your unit and confirm that our filters fit. All brand names, model numbers, and product images are the property of their respective owners; Isopure Water (IPW Industries Inc.) is not affiliated with, sponsored by, or endorsed by these manufacturers. We sell compatible replacement filters and parts — not the branded systems pictured, unless a system is separately listed for sale on our store.
