If you’ve ever noticed a pink or salmon-coloured residue around your bathroom sink, plughole, or shower drain, you’re not alone. Many households in Greater Vancouver see it regularly — especially in bathrooms — and it often comes back frustratingly fast after cleaning.
So what is it?
The short answer
That pink film is most commonly caused by a bacteria called Serratia marcescens. Despite sounding alarming, it’s very common, thrives in moist environments, and is not usually harmful to healthy people.
It isn’t mould, and it isn’t rust — though it’s often mistaken for both.
Why does it appear in bathrooms?
Serratia loves:
- Moisture and humidity
- Soap residue and shampoo build-up
- Warm, low-airflow spaces
That’s why it tends to show up:
- Around sink waste fittings
- Along shower grout and silicone
- In soap dishes and around taps
Vancouver’s naturally humid climate makes bathrooms an ideal environment for it to grow.
How to clean pink residue safely
At Lenuma, we focus on mechanical removal first, followed by low-residue treatment.
What works well:
- Wipe or scrub the area with a cloth or soft brush to physically remove the residue
- Apply a 3% hydrogen peroxide solution
- Allow it to sit briefly, then rinse and dry the area
Hydrogen peroxide is effective against bacteria, breaks down into water and oxygen, and leaves no harmful chemical residue — making it a good option for allergy-sensitive homes.
What to avoid:
- Bleach sprays (can aerosolize and irritate lungs)
- Harsh disinfectants with strong fragrances
- Spraying without wiping (this spreads bacteria rather than removing it)
How to prevent it coming back
The key is reducing moisture and residue:
- Dry sinks and taps after use where possible
- Rinse away soap and toothpaste residue regularly
- Improve ventilation — even cracking a window helps
- Clean little and often, rather than waiting for buildup
In regularly cleaned homes, pink residue becomes much less persistent.
A final word
Pink bacteria is one of those household issues that looks worse than it is — but it is a sign that moisture and residue are building up. With the right cleaning approach and consistent care, it’s easy to manage.
At Lenuma, we use thoughtful methods, low-impact products, and proven routines to keep bathrooms clean, healthy, and comfortable — without unnecessary chemicals.
If you’re seeing pink residue reappear regularly, we’re always happy to help.