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Allmost
09/22/2011, 11:05 AM
Hello,
are the ceramic plates reef safe ? how about the color on them ?

how about ceramic flower pots I see used in clownfish breeding tanks ?

do they put off any po4 or SI or ... ?

any experience and or advice is appreciated.

tired of buying frag plugs ... also need some larger ones I cant find anywhere .

thanks

PufferNut
09/22/2011, 12:47 PM
Having some background with ceramics I can tell you that the ceramic its self is totaly safe. The terra cotta pots in a tank work great. Plates SHOULD be ok as they are inteded for food use and should likewise have a neutral glaze that will not leach out. There are glazes that are not food safe, some lead based even, but I should hope your plates don't have that.

Allmost
09/22/2011, 12:51 PM
good point ! thanks,

the paint is food safe ... it has not came off ... I do have some fancy plates with lead on them !! some with copper too ! LOL supposed to be good for body ! I'll be sure to not use those.

I have a white plate soaking in RO/DI water right now, will test the po4 when I get home and if good I will use it

thanks

Toddrtrex
09/22/2011, 01:02 PM
I used ceramic tiles a couple of times -- for the clowns to lay eggs upon -- and never had any issues with them. Heck coralline started to grow on them.

Allmost
09/22/2011, 01:08 PM
ahhhh :headwally: lol

and I have a bunch of tiles left over at my parents after doing some reno there lol haha

thanks Todd, dont have to use my plates now :P lol GF will be happy hahaha

Toddrtrex
09/22/2011, 01:11 PM
Sure she will be very pleased. :)

An ancient picture (( or 6 years old ))

http://i5.photobucket.com/albums/y189/toddrtrex/eggs-1.jpg

sporto0
09/22/2011, 01:51 PM
Ceramic bits are actually used as a phosphate remover, I'm not sure if the solid smooth surfaces will absorb po4, if so there is a slight possiblity that prolonged submersion could result in leaching them back into the water, however I'm quite certain that ceramic material itself is harmless.

jlinzmaier
11/06/2011, 09:34 PM
I'd like to make some frag plugs and small rocks. I picked up some clay as well as some slip from my local pottery shop. I plan to just do a bisque fire (no glazing). Anyone have any literature or info on the safety of bisque fired clay?? When I tried talking reef chemistry to the lady at the pottery shop I got a pretty blank stare :D

Thanks.

Jeremy

PufferNut
11/06/2011, 09:56 PM
Depending on what type of clay you have the chemical composition is going to vary, and what might leech out changes. Still even bisque fired ceramic should be vitreous and not break down. Most all impurities burn off and leave you with basically glass.

What type of clay did you get?

Soak a fired piece in some ro-di and run some tests, but I'm pretty sure your gonna find nothing. Now that I think of it bisque fired stuff is gless likely than glazed to give off anything to the water, if just for the metals often used in tints for the glaze, copper being a popular one.

... oh how I miss working at the studio :/

jlinzmaier
11/07/2011, 09:21 AM
Depending on what type of clay you have the chemical composition is going to vary, and what might leech out changes. Still even bisque fired ceramic should be vitreous and not break down. Most all impurities burn off and leave you with basically glass.

What type of clay did you get?

Soak a fired piece in some ro-di and run some tests, but I'm pretty sure your gonna find nothing. Now that I think of it bisque fired stuff is gless likely than glazed to give off anything to the water, if just for the metals often used in tints for the glaze, copper being a popular one.

... oh how I miss working at the studio :/

Thank you for the reply!!

It was my understanding that the process of firing the clay essentially transformed the molecules of the clay to a crystalline structure which binds the molecules thus preventing any molecular leaching or adsorption.

I'm not sure what brand of clay I have. It's just what the pottery shop had in stock. Indicated to be "non-toxic" is the best description I can give you.

Appreciate your input!

Jeremy

PufferNut
11/07/2011, 08:50 PM
Yes, it should be that way with the crystalline structure as you stated. But as with anything there "grades" of ceramic, with different compositions. Likely you have earthenware clay, a very low temp fire. Tends to be more fragile because the lower temp makes for less fusion to simplify it a great deal. From the ceramic frag plugs I have gotten, they appear to be porcelain or stoneware, both much higher temp firing, and much harder.

The risk of leaching is almost nil, but if say someone had a gas fired kiln and inadvertently caused a reduction firing condition, carbon will build up in the pores of the bisque fired clay. But in electric kilns you have to try pretty hard to cause a reduction.

And the fact still remains that some glazes are explicitly not food safe. I read up in some of my books, and leaching from glaze usually is more prevalent in an acid condition, so it may not even be an issue.

jlinzmaier
11/08/2011, 07:23 AM
Yes, it should be that way with the crystalline structure as you stated. But as with anything there "grades" of ceramic, with different compositions. Likely you have earthenware clay, a very low temp fire. Tends to be more fragile because the lower temp makes for less fusion to simplify it a great deal. From the ceramic frag plugs I have gotten, they appear to be porcelain or stoneware, both much higher temp firing, and much harder.

The risk of leaching is almost nil, but if say someone had a gas fired kiln and inadvertently caused a reduction firing condition, carbon will build up in the pores of the bisque fired clay. But in electric kilns you have to try pretty hard to cause a reduction.

And the fact still remains that some glazes are explicitly not food safe. I read up in some of my books, and leaching from glaze usually is more prevalent in an acid condition, so it may not even be an issue.

Thank you very much!

Would I be better off looking for a high fire clay like cone 8 or cone 9 or would a low fire clay be just as good (I'm not all that concerned about strength since they are just frag plugs)?? Would a high fire create more fusion thus creating less potential for leaching or adsorption of molecules??

Also. I've gotten mixed reponses from local potters about how large of a piece of clay can be fired. The lady I bought my clay from wouldn't fire anything thicker than about a half inch but my friend went to a store local to him and there they said they could do larger rocks with little concern. I remember from high school pottery classes 15 years ago that we had to make our projects thin to reduce the chance of expolsion during the firing. What are your thoughts on how I could create rocks about the size of my fist or a bit larger (essentially to create frag stations).

What are your thoughts on using slip for puring into molds?? I have a cone 4 slip that seems to work well to create plugs that I made plaster of paris molds for. Is slip any different in composition that would make it less safe for reef application once fired to bisque?

Appreciate all your help. Very kind of you to be answering all my questions!!

Jeremy

PufferNut
11/09/2011, 08:44 PM
Yes, my thinking is that the high fire clay has less chance of leaching out anything. It is worth trying some low cone stuff and soak in rodi just for a test. I kinda doubt it will be a problem, but you never know.

Slip is great to work with in moulds. There is usualy a deflocculant added to casting slips, but I'm sure that burns off.

The tickness of what can be fired is kinda iffy. It's really more an issue of getting all the moisture out of the clay, and thus people are taught a certain thickness to ensure its all out.

for weight and drying factor, to make your large rock, you could try extruding clay out (think ultimate play-dough fun factory), and forming fluffy live rock like designs, or try to make a hollow form. You can hand build by making a couple pinch bowls and score and slip them together to make a sphere. With the air traped inside, you can then form it to different shapes. After it is very hard but still moist, you could cut holes for your frag plugs, keep in mind shrinkage.

You also could make a scuplture of a "rock" and cast it with plaster. Using slip you can then make a hollow form of that rock. I made a series of ceramic jugs from a cast of a glass one.

I need to find a local studio, I have some dreams of some diy ceramic lr

jlinzmaier
11/10/2011, 06:44 AM
Thank you very much!! Really appreciate you taking the time to provide some help. I know reefing in, out, and all around, but pottery is pretty foreign to me :D

Jeremy

Agu
11/10/2011, 09:44 AM
Why not DIY your own rock/plugs out of cement (http://www.reefcentral.com/forums/showthread.php?t=1704140&highlight=concrete) ? It's a proven technique that doesn't require any special knowledge or equipment.

fwiw ....

jlinzmaier
11/10/2011, 02:24 PM
Why not DIY your own rock/plugs out of cement (http://www.reefcentral.com/forums/showthread.php?t=1704140&highlight=concrete) ? It's a proven technique that doesn't require any special knowledge or equipment.

fwiw ....

I don't like the significant amount of cure time (leaching of hydroxide) nor do I like the texture of the concrete rocks.

Jeremy