Made by Think Crucial
Particle & Carbon Filter for Blueair Blue Pure 211+
★★★★★Amazon review
“These are very comparable to the brand name filters, at a MUCH better price! They work very well. …”
Shipping
Free U.S. shipping on every order
Dispatch
Ships in 1–3 business days
Fit
Fit guaranteed on the models listed
Returns
30-day returns
Check your model.
Type what's printed on your unit's rating label. The list narrows as you type, and only models we've listed come back as a fit.
It's on the rating label. Check the back, the base, or inside the filter door, and type the MODEL NO. line exactly as printed. The drawing is a guide; your label may sit elsewhere.
Fits these models 2 listed
- Blue Pure 221
- Blue Pure 211+
Looks similar, doesn't fit
- Blue Pure 211i Max Uses a different filter.
Don't see your model? Compatibility not confirmed. Email support@thinkcrucial.com with the model number from the label before you order, and we'll tell you whether this fits.
Fit list checked Oct 2026 against manufacturer and parts-catalog sources
Brand and model names are used only to show compatibility. Think Crucial is an independent brand, not affiliated with those manufacturers.
The spec sheet.
- Fits
- Blue Pure 211+, Blue Pure 221
- Replace
- Every 6 months · Blueair's 211+ filter light: change after about 6 months of use
- Made by
- Think Crucial (aftermarket, not affiliated with Blueair)
Think Crucial vs. Blueair's own.
We only quote the other brand's price once we've checked it and can show you where.
| What | Think Crucial | Blueair's own filter |
|---|---|---|
| Fits the models listed | Yes, listed and fit-guaranteed | Yes |
| Price | $51.99 with free U.S. shipping | Not quoted |
| If it doesn't fit | Prepaid return label, full refund, 30 days | Blueair's own terms |
| Made by | Think Crucial | Blueair |
Aftermarket means we make the part to fit the models listed. It isn't made by or affiliated with Blueair. You get the same job done with our own build, and our fit guarantee on top.
When to replace it.
Basis Blueair's 211+ filter light: change after about 6 months of use. Heavier use shortens it.
What happens if you wait
- Month 6Blueair's 211+ filter light: change after about 6 months of use.Why it matters: a loaded filter reduces airflow.EPA, Residential Air Cleaners
- CarbonThe carbon layer.Why it matters: a full carbon filter “may release trapped pollutants back into the air.”EPA, Guide to Air Cleaners
What owners say.
On thinkcrucial.com
On Amazon
4.6 out of 5 from 130 ratings on Amazon (as of Oct 1, 2026)
“These filters are a great alternative to Blueair-branded accessories, … I've noticed no difference in quality or filtering ability. Highly recommended.”
“These are very comparable to the brand name filters, at a MUCH better price! They work very well. …”
Ratings and reviews from Amazon.com for the same Think Crucial product, as of Oct 1, 2026. They are separate from reviews on this site and aren't counted in them. Excerpts are quoted word for word.
Before you order.
Shipping, returns and fit work the same on every product.
Q01Will it fit my machine?
It's listed for Blue Pure 211+, Blue Pure 221. If your label shows a different model, compatibility isn't confirmed: email support@thinkcrucial.com with the model number before you order. If a listed model doesn't fit, we send a prepaid return label and refund you in full.
Q02Is this an original Blueair part?
No. It's an aftermarket filter made by Think Crucial to fit the models listed. Think Crucial is not affiliated with Blueair. We make what we sell.
Q03What if it doesn't fit, or I change my mind?
If it doesn't fit the model we list, we email a prepaid return label within 30 days of delivery and refund you in full; opened to test the fit is fine. Changed your mind? Return it unused in its original packaging within 30 days of delivery. The return label is free for these too.
Q04When will it arrive?
Shipping to U.S. addresses is free on every order. It ships from our fulfillment center in 1–3 business days and arrives in 3–7 business days.
Q05Is there a subscription?
No. You buy one when you need one. Nothing renews and nothing auto-ships.
Q06What's in the box?
The 1 Pack has one particle-and-carbon filter for the Blue Pure 211+. The 2 Pack and 4 Pack have two and four.
Q07How often do I replace this filter?
Blueair says the red filter light on its 211+ comes on when it's time to change the filter, after about 6 months of operation. That's Blueair's schedule for its own filter.
We make what we sell.
Think Crucial started in 2007 at a family vacuum repair shop. Today we make aftermarket filters, bags and parts built to fit the machines you already own, plus our own descalers and cleaners. Most people can fit the part themselves. They just need the right one, and a way to check it first.
- Find the model number on the rating label
- Match it to the list on this page
- Not listed? Ask us before you order
Ready to order
Particle & Carbon Filter for Blueair Blue Pure 211+
Fits Blue Pure 211+ · Blue Pure 221
$51.99Free U.S. shipping
Fit guaranteed: prepaid return label if it doesn't fit the model we list. 30-day returns.
Full product description
TOP BENEFITS OF AIR PURIFIERS INCLUDE LONG LASTING, RELIABLE, AND BETTER AIR QUALITY. THEY ARE EASY TO INSTALL FOR MAXIMUM DURABILITY AND HEALTHIER LIVING.
Also compatible with: Blueair models Blue Pure 221.
Brand and model names are used only to show compatibility. Think Crucial is an independent brand, not affiliated with those manufacturers.