ceramic inert?

[terror]

just wondering, are ceramic tiles inert?

 

[OrionGirl]

Glazed or unglazed? Unglazed will absorb some water and may increase pH--will depend on how it was fired, I think. Some glazes are not inert--testing the object in a bucket of water will be your best bet.

 

[terror]

thanks! i was plannning to get unglazed ones...
i'm trying to avoid reflection from the buttom of my tank