Are Ceramics Safe For Saltwater?

[Dahlia]

Have any of you put ceramic ware in your tank (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?

 

[Xzibit]

Well I dont know for sure how safe it is, I have seen Terra Cotta pots in Tanks in a LFS that had Mated Clowns in them. Also I just got a Nano Cube and it came with ceramic Tube like meda for the filter. I dont think either of these had any kinda glaze on them though. I know that does not help much so hopefully someone else could add a little more info for you.


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[Dahlia]

Thanks!

I'm especially interested in finding out if they are prone to long term deterioration. Such as, if someone put a glazed pot in their tank and its still there 10 years later. But any accounts of successful/unsuccessful ceramic in the aquarium are helpful!

 

[TKOS]

They are mostly prone to problems when they are removed from the tank and allowed to dry out. What happens is that after awhile the salts in the water penetrate the ceramic and if allowed to dry come out of solution and expand in size which can cause the ceramic to break apart.

Make sure the glaze is unleaded and contains no other harmful substances like cadmium.

 

[Dahlia]

So they function fine while they are in the aquarium, and only have problems if they are removed? Do you know if soaking them in fresh water after removing them from a salt tank would remove salt from the piece and keep it from breaking?

I presume most people don't worry too much about this, but I'm curious what would happen to ceramic art sculptures over a long term period if they are submerged in saltwater.

 

[TKOS]

That is part of what I do for a living. Yes, fresh water baths are very common way of getting out salts from ceramics. We use a little meter that measures salt content and keep doing it until we get about the same amount of salt in the wash water that you would get in tap water. Otherwise watch those things fly apart. And it can be years later depending on the humidity changes.

The washes can take quitye awhile. If you ever want to clean off a cermaic that has been in salt water for a long time a quick trick is to place it in your toilet tank. Each time you flush it gets a nice new bath of freshwater. Leave it there for a few weeks and you should be good (unless you don't flush very often, and no blue toilet dye stuff either).

 

[Dahlia]

I hope I am not being too nosy, but could you tell me a little more about the ceramics you are used to dealing with? How much time do they typically spend under the water? They really don't experience much if any wear during that time? This has been great info... the toilet thing is amusing.

 

[TKOS]

I work on the East Coast of Canada so most of the ceramics that we deal with are from the early 1700's and up. A lot fo them come from the ground right next to the coast so they have been through heck. But the salt water itself really doesn't hurt them. If they are in deep enough water they are generally in fine condition. Shallow water can often mean wave action has hurt them quite a bit.

Of course out in the mediteranean they spend many centuries if not over a thousand years under the sea and often come up in fine condition. It is just a matter of keeping them wet at all times and getting the salts out through fresh water washes.

Glass is a lot trickier than ceramic (and therefore glazes can sometimes be a problem). This is due to the fact that many older glasses and glazes contained the wrong proportions of fluxes and fillers and water can actually leech them out, leaving the glass weak and brittle.