Do Ceramics Deteriorate Over Time in Freshwater?

Dahlia

Dahlia

AC Members
Sep 3, 2003
378
0
0
48
South Carolina
www.livejournal.com
Have any of you put ceramic ware in your tank (this can include terra cotta pots, but I'm especially interested in stoneware type pottery) and if so how long has it been in your tank? Have you ever experienced deterioration such as cracking, flaking, etc.? Do food safe glazes negatively affect tank water?
 
I have had a terra cotta pot in my tank for about 2 years, but as far as I know, ceramic is perfectly inert, and food safe glazes are as well.
 
Yeah, I've had some terra cotta in my tank for about 4 years now... and other than the fact I broke chunks out of them as cave openings before I put them in the tank they have held up perfectly. I think I've heard food safe glazes are okay for tanks as well, but even some of the food safe ones are made with heavy metals so I wanted to be sure.

I'm interested in anyone's personal accounts with ceramics in the aquarium, but I'm particularly curious if anyone has had a glazed ceramic item in their tank with no problems for a long while... say 10+ years or more. I want to know how they tend to hold up long term.
 
Unglazed ceramics, like terracotta pots are fine and perfectly stable. In general glazes are discouraged because 'food safe' means that over a short period of time (like a few hours) the glaze will not release an amount of heavy metals or toxins harmful to humans.

Trying to extrapolate that to say that when left submerged in water for weeks, months, years will not be harmful to fish is tricky at best.

That doesn't mean that they are bad, just that while the label 'food safe' is better than nothing, it doesn't necessarily mean 'aquarium safe'.
 
I've seen glazed ceramics for the aquarium, so I am hoping at least some glazes would be okay... I assume the ones with heavy metals in them are to be avoided. I wonder where I could find out which ones are okay.
 
Dahlia said:
I've seen glazed ceramics for the aquarium, so I am hoping at least some glazes would be okay... I assume the ones with heavy metals in them are to be avoided. I wonder where I could find out which ones are okay.
Click to expand...

well, for what it's worth, the Food and Drug Administration regulates food-purpose ceramics, so if you could call your local office, or you can look it up on www.fda.gov to see what colors/glazes usually contain heavy metals

Also, I'm not sure how available they are commercially, but I do know that there are test kits on the market, where you can rub a bit with sandpaper, and the test (usually a combination of two reagents) will change color if there are heavy metals like lead present.
 
You must log in or register to reply here.
AquariaCentral.com
Top Bottom