No worries! It's just mineral salts aka efflorescence.
Today, I was dismayed to see this from a customer. I wish they had called or emailed me! They left this feedback on a blog post:
#1 L**** B***** : Stefani Water purifier - feedback
Good afternoon,
The year before last I purchased the Stefani Water purifier as a gift for my daughters. They at first weren't impressed with the taste of the water but they decided to keep using it anyhow due to the fluoride in the city water. After visiting last weekend, I noticed that there was a white mould or fungus growing on the exterior of the purifier. They've let it completely empty and dry out yet the fungus is still there and now they refuse to use it (understandably). Not exactly what I expected for a fairly pricey product.
While there are a number of misconceptions in the comment, I want to address the primary reason they stopped using their Stefani: White Stuff.
The white stuff is efflorescence, not mould.
I responded:
Hello L***,
I just now saw your comment about your water purifier on a blog entry my website. I am sorry that you've had this experience and I wish I had been able to answer your concerns directly.
What you are seeing is not fungus, but efflorescence, which is to say minerals such as salts and calcium that are left on the surface of the unglazed terra cotta as water evaporates through the pores.
Efflorescence is a crystalline deposit of salts that can form when water is present in or on brick, concrete, stone, stucco or other building surfaces. It has a white or greyish tint and consists of salt deposits that remain on the surface after water evaporates.
It is normal. That's why I tell people to wipe the water purifier down each day as you wipe down your kitchen counters.
I refer you to this video simply to show you that efflorescence is normal for terra cotta. I am not suggesting that you have to soak your Stefani in vinegar!
How to Remove White Stuff from Terra Cotta Planters
EWW! What's that White Stuff on my Terra Cotta Pots!?
Here is a video from the company about how to maintain the Stefani. Many people don't read the maintenance instructions, so I do try to emphasize how to set up and maintain the water purifier when a customer buys one in the shop. If you gave the water purifier as a gift, then it's possible the info was not passed on.
Would you please forward this email to your daughters and ask them to get in touch with me by email? I can then follow up with them by phone as to how to get their water purifier working.
We use three Stefani water purifiers at Anarres to make our body care products with and as such the water is tested for microbes. Simply put, if there were any mould in the water, our body care products would fail!
I've had my first Stefani water purifier for 12 years now and I want everyone who has one to enjoy it as much as I do.
I apologize for not seeing your comment sooner, and I hope to be able to help you fix the situation soon.
Thanks, Tracey
Please, if you have any trouble whatsoever with your Stefani water Purifier, get in touch with me by email Anarres Health AT gmail DOT com or come into the shop! I will help you make it right.
Don't forget to watch this thorough customer review: