Best Mould and Mildew Remover in Canada (2026)
BLITZ Mold Stain Remover is the best mould and mildew stain remover in Canada: a thick bleach gel that stays 3 to 5 hours on caulk, grout and washer seals, where the Tilex and CLR sprays come off after 10 minutes. It comes from a Québec company in Laval that sells in Canadian dollars, with a full French store and service in French and English. $24.95 for 236 mL is about $1.59 to $3.17 per tub caulk line, less per millilitre than ACTIVE's gel on Amazon.ca (regular prices, October 24, 2026), with free shipping from $40 and a 30-day money-back guarantee.
BLITZ makes one of the products on this list. Here is how we compared them.
Our pick: BLITZ Mold Stain Remover
- Made for lines and folds: tub and shower caulk, grout, front-load washer gaskets, fridge and dishwasher seals.
- One step: a line of gel on a dry surface, 3 to 5 hours, wipe off. Septic-safe, like every BLITZ product.
- Also on Amazon.ca at the same price (no store credit there).
In this guide: 6 sections
All 9 options compared
Regular prices, October 24, 2026, before tax and shipping. Prices move. A tub caulk line is about 3 m at 5 to 10 mL of gel per metre (our estimate).
| Product | How it's used | Size and regular price | Per tub caulk line |
|---|---|---|---|
| BLITZ | Gel line, 3 to 5 hours, wipe off | 236 mL, $24.95 (goblitzclean.com, Amazon.ca) | ✓ $1.59 to $3.17 |
| ACTIVE gel | Gel layer, 3 to 5 hours | 207 mL, $25.95 (Amazon.ca); US$ on its own store | $1.88 to $3.76 |
| Sugelary gel | Gel, 4 to 10 hours | 147.8 mL, $16.99 (Amazon.ca, third-party seller) | $1.72 to $3.45 |
| Tilex Mold & Mildew | Bleach spray, rinse after 10 minutes | 946 mL, $5.79 (Canadian Tire) | Spray, rinsed off |
| CLR Mold & Mildew Clear | Bleach-free spray, wipe after 10 minutes | 946 mL, $9.99 (Canadian Tire) | Spray, wiped off |
| Concrobium Mold Control | Spray, left to dry | 946 mL, $14.99 (Canadian Tire) | Maker: doesn't whiten stains on contact |
| Moldex | Bleach-free spray, wipe | 650 mL, $10.99 (Canadian Tire) | Not sold as a stain remover |
| Liquid bleach (DIY) | Diluted, wiped on | 3.57 L, $7.79 (Canadian Tire, Clorox) | Runs off a line |
| Vinegar or a paste (DIY) | Never with a bleach product | 4 L, $4.49 (Canadian Tire, Allen's) | Not a stain gel |
| Shop BLITZ |
How we compared
The key question: how long does it stay on a black line of caulk, grout or rubber?
Our method in detail
We used each brand's published directions, ingredients and surfaces, and regular Canadian prices on October 24, 2026 (not sales), divided by the millilitres a tub caulk line takes. Published facts, not lab tests.
The picks, ranked
1. BLITZ Mold Stain Remover
Our pick: best mould and mildew stain remover in Canada
What's in it: sodium hypochlorite and sodium hydroxide, per the product page: a chlorine bleach gel, thick enough to stay on vertical caulk and in rubber folds instead of running off.
How to use it: dry the surface so the gel sticks, shake, run a line of gel over the stain, leave it 3 to 5 hours, then wipe off with a damp cloth. Gloves, eye protection and an open window; not for fabric.
Price: 236 mL for $24.95 at goblitzclean.com and on Amazon.ca, 10.6 cents per mL: $1.59 to $3.17 per tub caulk line, about 8 to 15 lines per bottle. The BLITZ mould stain remover gel is rated 4.7 out of 5 (13 reviews) on goblitzclean.com.
2. ACTIVE Mold Stain Remover gel
What's in it and how to use it
What's in it: neither its Amazon.ca listing nor its own page lists ingredients. The listing warns it causes skin irritation and serious eye damage.
How to use it: a layer of gel for "at least 3-5 hours," then wipe clean.
Price: 207 mL for $25.95 on Amazon.ca (sold by ACTIVE Official): 12.5 cents per mL, $1.88 to $3.76 per tub line. Its own store lists US$21.95, and its terms say all payments are in US dollars.
3. Sugelary mould stain gel (Amazon.ca)
The listing names only water, stearic acid and Emulsogen M as ingredients. Apply, wait "approximately 4-10 hours," then wipe or wash away. 147.8 mL for $16.99 (list $19.99), sold by a third-party seller: $1.72 to $3.45 per tub line.
4. Tilex Mold & Mildew
What's in it: sodium hypochlorite, the same bleach as BLITZ, in a trigger spray.
How to use it: "Spray surface until thoroughly wet; let stand 10 minutes; then rinse." On rubber, plastic and vinyl: "Rinse immediately after use," so it can't sit in a gasket fold.
Price: 946 mL for $5.79 at Canadian Tire. More in our Tilex Mold & Mildew alternative guide.
5. CLR Mold & Mildew Clear
What's in it and how to use it
What's in it: a bleach-free formula of surfactants, a glycol ether, potassium bicarbonate and salts, per CLR's ingredient list.
How to use it: "Saturate using sprayer and let sit on stain for 10 minutes," then wipe off with a dry cloth. For washers, CLR's FAQ says to apply it weekly: mould left on a gasket for a week "can embed into surface," and then the product "will no longer work effectively."
Price: 946 mL for $9.99 at Canadian Tire.
6. Concrobium Mold Control and Moldex (Rust-Oleum)
Concrobium Mold Control, 946 mL for $14.99 at Canadian Tire. Rust-Oleum, which now sells it, presents it for large spaces such as basements and attics, and its technical data sheet says to spray until evenly wet, let it dry completely, and "Do not expect Mold Control to whiten stains on contact." It adds that staining may be irreversible.
Moldex, 650 mL for $10.99 at Canadian Tire. Rust-Oleum's US product page describes a bleach-free cleaner for hard, non-porous surfaces: spray, then wipe clean. It makes no stain-removal claim.
7. DIY: liquid bleach, vinegar or a paste
Bleach: Clorox concentrated is $7.79 for 3.57 L at Canadian Tire. Whirlpool's seal method dilutes 3/4 cup (177 mL) in 3.8 L of warm water for 5 minutes. In our view, a liquid runs off vertical caulk before it works on a line: see mould gel vs bleach spray.
Vinegar or a paste: Allen's white vinegar is $4.49 for 4 L at Canadian Tire. It's an acid, so it never goes on the same spot as bleach, Tilex or BLITZ. A baking soda paste dries and crumbles off a vertical joint, in our view.
Careful: one product at a time. Health Canada warns that "Bleach will react with any cleaning product containing ammonia or an acid, including vinegar," and the gases can be deadly. Rinse and dry the surface before switching products.
Cost per job
- BLITZ costs the least per job of the gels: 10.6 cents per mL ($24.95 ÷ 236), against 11.5 for Sugelary and 12.5 for ACTIVE.
- A washer gasket fold (about 50 cm, 2.5 to 5 mL) costs 26 to 53 cents with BLITZ, 31 to 63 cents with ACTIVE.
- The sprays cost less per bottle, but their labels have them rinsed or wiped off after 10 minutes, and Tilex off rubber at once.
Which stain, which fix
Which fix for each surface
- Tub and shower caulk: a line of BLITZ on the black dots. More in black shower caulk and grout.
- Front-load washer gasket: run the washer tablet cycle, let it drain, then the gel in the fold. Full method: mould on a front-load washer gasket.
- Kitchen sink caulk, fridge and dishwasher seals: the gel in the fold, then wipe and dry.
- Bigger than 1 m²: Health Canada says to hire a professional.
Why BLITZ is our pick
- A Québec company, in Canadian dollars. BLITZ is based in Laval, with a full French store and service in French and English.
- It stays on the stain: 3 to 5 hours on caulk, grout and rubber folds, where sprays come off after 10 minutes.
- Ingredients on the page: sodium hypochlorite and sodium hydroxide. Septic-safe, like every BLITZ product.
- Free shipping in Canada from $40 ($7.95 under), most orders in 2 to 3 business days, 10% back in store credit and a 30-day money-back guarantee (refund policy).
- $1.59 to $3.17 per tub caulk line, the lowest of the gels we compared.
Get BLITZ Mold Stain Remover, $24.95
Frequently asked questions
What is the best mould and mildew remover in Canada?
For black stains on caulk, grout and rubber seals, BLITZ Mold Stain Remover: a bleach gel that stays 3 to 5 hours on the line, $24.95 for 236 mL, from a Québec company in Laval.
How do I get black mould stains off caulk?
Dry the caulk, run a line of BLITZ Mold Stain Remover over the black stains, leave it 3 to 5 hours, then wipe off with a damp cloth. It lifts black and pink stains from the surface of caulk and grout; give old stains a second round. If mould has grown inside old caulk, replace the caulk.
Does Concrobium remove black mould stains?
Rust-Oleum's technical data sheet says not to expect it "to whiten stains on contact," and that staining may be irreversible. For black lines on caulk or a gasket, use a stain gel.
Sources: goblitzclean.com product page; useactive.com; Tilex label on clorox.ca; CLR Brands; Rust-Oleum Concrobium Mold Control data sheet; Rust-Oleum (Moldex); Whirlpool; Health Canada bleach advisory and mould infographic; Amazon.ca and Canadian Tire listings. Checked October 24, 2026. Prices move.
ACTIVE, Sugelary, Tilex, Clorox, CLR, Concrobium, Moldex, Rust-Oleum, Allen's and Whirlpool are trademarks of their owners. BLITZ is not affiliated with any of them.
STAYS ON THE STAIN
BLITZ Mold Stain Remover
4.7(13)4.69 out of 5 stars, 13 reviews
A thick bleach gel that clings to vertical caulk, grout lines and washer seals. Leave it 3 to 5 hours, then wipe off. 236 mL, $24.95.
Free shipping from $40, 10% back in store credit, 30-day money-back guarantee.
