i would be HIGHLY skeptical about putting cat litter in a tank...there are so many additives they put in it beyond just clay, and there'd be no way to tell if they're all aq safe. maybe if it were a plant-only tank to grow plants for another aquarium, but even then, there are much more effective fertilisers for your plants
So remember, when you're feeling very small and insecure,
How amazingly unlikely is your birth,
And pray that there's intelligent life somewhere up in space,
'Cause there's bugger-all down here on Earth.
Loki/Grendel/Gail/Beowulf/Camilla/River/Bathory/Arwen/Lafayette/Deb/Jack Skellington (soon)