ceramics in aquarium

[Dahlia]

If I were to make my own ceramic caves and fire them in a friend's kiln, would they do anything bad to my water? Should I glaze them or leave them bare or does it matter? Does anyone know if there is a specific kind of clay I should use? Would any food-grade clay be safe?

 

[SimonWoodstock]

i'm not an expert on pottery but i have a friend that was into it for a while. i would think it should be ok to put in your tank...glazed or not. i would just make sure it was washed off really good before you put it in there.

as for the type of clay, ask your local hobby shop what kind to use...or your friend w/ the kiln may know. my friend used to give some guy that made pottery for a living a little money and he would get several pounds of the clay to use. not sure about the price but i am pretty sure it was farely cheap.

 

[fishfood]

I'm also not an expert on pottery but I remeber from HS art class that there were two kinds of glaze that we used. One for decorative object and one for bowls, glasses, etc. that you may use for food or beverage. The former contained lead that could leach out of the glaze into the food or water. The later didn't contain lead and supposedly didn't leach chemicals.

Unless they've banned lead from glazes, I would think that you would want to pick the lead free type so that it won't leach into the water.

 

[TomFromStLouis]

Leaded glazes are not sold in the US anymore. Once fired, unglazed clay is an inert as rock and as you know the wrong rock can leach into your water. Still, I can't think of a clay body that would be too limey.

Glazes are essentially glass, so glazed stuff (which all those cheesy castles and mermaids used to be made of) would be okay.

"Food grade' ceramics basically means glazed with a nonporous glaze. I think glazed caves would be a little easier to maintain - fewer tiny pores for microorganisms or algae to live in.

 

[Dahlia]

Thanks, very helpful!

 

[Dahlia]

Hey, I just thought I'd add to this that I spoke with my friend with the kiln yesterday (she majored in ceramics and teaches it at a local college). She told me that leaded glazes are still sold in the US, so if anyone else decides to try this make sure that you find a glaze that is lead-free.