Stalactites?

[FyaNyan]

Hello.

I am cleaning out my fish tank. It’s always had an algae problem. This summer I was very distracted from keeping up tank maintenance and the algae must have sat for a few months. When I pulled off the lid, there are soft, springy, dark stalactites growing from the lid, about half an inch long. Is this a typical algae formation? Or is something more sinister going on? Has anyone else experienced this?

[Fish Folk]

It’s common. Moisture meets green growth there, and drips continuously.

[lefty o]

some crud growth is normal.

[Tanked]

On 9/6/2023 at 9:20 PM, FyaNyan said:

Hello.

I am cleaning out my fish tank. It’s always had an algae problem. This summer I was very distracted from keeping up tank maintenance and the algae must have sat for a few months. When I pulled off the lid, there are soft, springy, dark stalactites growing from the lid, about half an inch long. Is this a typical algae formation? Or is something more sinister going on? Has anyone else experienced this?

I've never had stalactites on the lids.  I have BBA stalactites growing off one of the HOBs occasionally.  The fish love it.

[FyaNyan]

Oh, good. I am glad it is nothing to worry about. I’d just never seen that much buildup before! Thanks everyone 🙂