Indeed. But it's got no nutrients...

Here's why i've adopted such aquarium artifact:

1) It breaks splashes while watering
2) It doesn't allow mold to grow on it
3) It reflects back blue and red light
4) It makes photo sessions pleasant

Here's a somewhat more obvious sample:

Attachment 281020

But really, this one is my favourite so far:

Attachment 281019

Ain't she sexy on a stage like that one?!...