Mold doesn’t need light (quite the opposite: UV exposition might even inhibit mold).
But a clear tank helps determining if it is clean. And also if it is empty.
BTW: OP almost certainly did not have mold, but algae.
Had that myself once, coffee maker is placed right at a window…
Why did they make it a clear tank? Thats designed to breed mold. Wow.
Mold doesn’t need light (quite the opposite: UV exposition might even inhibit mold).
But a clear tank helps determining if it is clean. And also if it is empty.
BTW: OP almost certainly did not have mold, but algae.
Had that myself once, coffee maker is placed right at a window…
Yes sorry, I did mean algae. All the coffee makers I think of have a black plastic tank. Some have a little window to see the water level.
Better than opaque where the average person who doesn’t pay attention to anything would never see it.
My bigger complaint is the weird shape that’s hard to clean with either a dishwasher or by hand.
My machine has a simple rectangular one where the end is open - easy to wash by hand or in dishwasher.