StareDownMeg Posted March 7, 2012 Report Share Posted March 7, 2012 Hello, I am wondering if anyone can tell me from first hand experience if hand-made ceramics are safe for fish tanks? I have been doing ample research and finding widespread opinions/advice. The answers have ranged anywhere from "no, you should only use things marked "aquarium safe"/glazed are harmful and overtime will release harmful chemicals into your tank" to "as long as work is fired to cone *insert various numbers, nothing consistent*" or unglazed is okay. And some say as long as glazes are food-safe. Thank you in advance! Link to comment Share on other sites More sharing options...
Guest JBaymore Posted March 7, 2012 Report Share Posted March 7, 2012 Having kept a marine aquarium for many years, I can understand your concern. My heavy ceramics technical background says that the answer is not as simple as you'd like. IF the ceramist knows what she/he is doing with glaze formulation, and maintains the use of appropriate sealing compounds where ceramic and glass meet, then there should be no problem at all. GOOD glazes are about as stable as most glass. (Not all glass is stable wither.) If the interior glaze(s) do leach however........ it depends on WHAT they leach into the water as to the potential impacts on the fish/ invertibrates/ etc.. And how MUCH they leach over what time period (relative to tank water changes that will dilute any lechate buildup). There is also the question of if this is a fresh water or marine aquarium? The amouint of potential leaching could be affected by that. Since the general Ph of the aquarium water can vary a bit, we are also not talking about simply typical tap water. If someone is not attentive to cleaning the tank as often as should happen, then the rate of potential leaching would likely change with the Ph. (But that would be bad for the fish in ANY tank .) Contact Robert Comptop about this. He made aquariums for years: http://robertcomptonpottery.com/Sold-Architectural-Potteryk.htm He should have some suggestions/ insights. Hope this helps....... but just might raise more questions . best, ...............john Link to comment Share on other sites More sharing options...
StareDownMeg Posted March 7, 2012 Author Report Share Posted March 7, 2012 Having kept a marine aquarium for many years, I can understand your concern. My heavy ceramics technical background says that the answer is not as simple as you'd like. IF the ceramist knows what she/he is doing with glaze formulation, and maintains the use of appropriate sealing compounds where ceramic and glass meet, then there should be no problem at all. GOOD glazes are about as stable as most glass. (Not all glass is stable wither.) If the interior glaze(s) do leach however........ it depends on WHAT they leach into the water as to the potential impacts on the fish/ invertibrates/ etc.. And how MUCH they leach over what time period (relative to tank water changes that will dilute any lechate buildup). There is also the question of if this is a fresh water or marine aquarium? The amouint of potential leaching could be affected by that. Since the general Ph of the aquarium water can vary a bit, we are also not talking about simply typical tap water. If someone is not attentive to cleaning the tank as often as should happen, then the rate of potential leaching would likely change with the Ph. (But that would be bad for the fish in ANY tank .) Contact Robert Comptop about this. He made aquariums for years: http://robertcompton...al-Potteryk.htm He should have some suggestions/ insights. Hope this helps....... but just might raise more questions . best, ...............john John, Thank you. I completely forgot to mention it will be a freshwater tank. Thank you for the advice, very helpful. Now the question of just simply fired stoneware without any glaze, should that be safe on its own? I am heading over to Robert Comptop's site to further investigates. More questions are no problem, it is better to do research first before potentially harming the fish! (The fish that I don't even have yet). I just really don't enjoy any of the mass produced trinkets and toys to put into tanks.... I'd rather have my own designs in there. Link to comment Share on other sites More sharing options...
sprig Posted March 7, 2012 Report Share Posted March 7, 2012 youll probably get a better answer at here: http://www.fishgeeks.com/tropicalfishforums/viewtopic.php?t=45758 if a person that has kept an aquarium for years and has a techniucal background in ceramics cant give you a straight answer who can? Link to comment Share on other sites More sharing options...
Guest JBaymore Posted March 7, 2012 Report Share Posted March 7, 2012 youll probably get a better answer at here: http://www.fishgeeks...pic.php?t=45758 if a person that has kept an aquarium for years and has a techniucal background in ceramics cant give you a straight answer who can? Like all internat forums, there is some inaccurate stuff mixed in there amongst a few accurate pieces of info (simply from a ceramics point of view). Paul Lewing and I have presented at NCECA together along with Ron Roy many years ago.... Paul knows his stuff..... so listen to him. The last posting (when I just read it) mentions that lead and barium are regulated by "law". This is untrue... unless something has changed in the VERY short term that I do not yet know about. The only two compounds that are regulated in fired glazes in the USA are lead and CADMIUM. Barium is not. If you use lead and cadmium and you sell your work in the USA you need to comply wit thhe FDA's regulations. See FDA.gov for info on how to comply. (If you sell in California, they have tighter standards.) best, ............john Link to comment Share on other sites More sharing options...
AmeriSwede Posted March 8, 2012 Report Share Posted March 8, 2012 youll probably get a better answer at here: http://www.fishgeeks...pic.php?t=45758 if a person that has kept an aquarium for years and has a techniucal background in ceramics cant give you a straight answer who can? Like all internat forums, there is some inaccurate stuff mixed in there amongst a few accurate pieces of info (simply from a ceramics point of view). Paul Lewing and I have presented at NCECA together along with Ron Roy many years ago.... Paul knows his stuff..... so listen to him. The last posting (when I just read it) mentions that lead and barium are regulated by "law". This is untrue... unless something has changed in the VERY short term that I do not yet know about. The only two compounds that are regulated in fired glazes in the USA are lead and CADMIUM. Barium is not. If you use lead and cadmium and you sell your work in the USA you need to comply wit thhe FDA's regulations. See FDA.gov for info on how to comply. (If you sell in California, they have tighter standards.) best, ............john An additional note regarding the "answers on that linked posting"… …. is that the FDA's regulatory term 'food-safe' ONLY refers to lead and cadmium [this information is derived from Hesselberth/Roy's book 'MASTERING CONE 6 GLAZES', alluded to by P. Lewing in his response and clarified by John's posting above). Of course, California has more stringent regulations in the area of 'food safe', which would probably be a better guide considering the known corporate corruption existing in the FDA. Also as John mentioned earlier the 'pH level of the water'… in addition to the durability of the glaze has much to do with the "fish" safety as well. Fish are not people and being organisms to the scale of n/hundredths less in mass can be affected by significantly smaller quantities of pollutants/heavy metals than we are. Also the FDA's regulations of leaching limits vary as to what the intention of the ceramic article is designed for (ie., flatware, hollowware, pitchers, cups & mugs, etc.). As 'food safe', we're concerned with ingestion only. The fish would not only be subjected to ingestion but also by direct contact/absorption through their water environment itself, if metals leaching occurred. This could possibly result in scale (skin) lesions or possibly other maladies as well. We only have our natural environment to look at for evidence of this. Since most commercial glaze recipes are trade secrets one is left in the dark as to the knowledgeable use of cobalt, copper, chromium, etc., that may be used for colorants and whether or not their 'food safe' glaze leaches any degree of that. If the glaze is NOT stable on your particular clay and leaching does occur…. How much heavy metal will your fish be able to absorb (in its confined environment) before it is adversely affected? That opens up another door! One will then need to find an expert in ichthyology (also well versed in glaze production/manufacture) to offer the most ideal lower limits of heavy metal pollution allowable (species specific?) for 'aquarium fish safe' glazes! Personally, if I had an affliction for maintaining an aquarium and also had an addiction to create using ceramic, I would just utilize the best medium- to high-fired clay that showed the lowest absorption after firing, with which to make my (unglazed) ornamentation. As time went on and that particular piece became more grimy and couldn't be cleaned well enough for my 'wants'… I would just make a new and different item to replace it. Kind of like changing that painting behind the sofa on occasion…. Link to comment Share on other sites More sharing options...
Guest JBaymore Posted March 8, 2012 Report Share Posted March 8, 2012 Ameriswede... good stuff. Also note here that there is a difference between the definitions of "lead safe" and "lead free" in the definition of commerical glazes. They are not synonomous. "Lead safe" glazes do contain lead compounds. When applied and fired to the EXACT manufacturers specifications they have been tested to typically show lead release below the FDS's (or California's Prop 65) standards. So the handling of "lead safe" glazes still poses a potential risk to the potter even if the consumer is potentially somewhat protected. As Ameriswede points out...... what exactly will hurt the fish? best, ...................john Link to comment Share on other sites More sharing options...
maorili Posted March 8, 2012 Report Share Posted March 8, 2012 I am not an expert for fishes, but I made ceramic deco for my freshwater aquarium (only simple 100l) It is no Problem for now nearly two years. I used a light grey clay and brown slip (which is indicated for dishes too) and red slip. Everything is now darker because of the algues, but looks very nice and natural. I think it adds value to my Aquarium because the bacteriums which are in the filter medium can live also on the surface of the clay, if it is still porous. Maybe I am wrong, but fishes are always healthy. after building fresh clay with new plants (newly arranged and planted) after a month old cat on warm aquarium.. she loves it. Greetings from Germany (and sorry for my bad English) Gabi Link to comment Share on other sites More sharing options...
Darla Posted March 8, 2012 Report Share Posted March 8, 2012 I haven't had any problems either.... I've had 5/6 stoneware, glazed with food safe commercial glazes in my freshwater tank, even my baby tank, forever. Darla Link to comment Share on other sites More sharing options...
AmeriSwede Posted March 9, 2012 Report Share Posted March 9, 2012 so StareDownMeg... (et al) You can see the quandary on attempting to act on information derived from internet forums (and for the most part-the world at large), with the diversity of knowledgeable and seemingly knowledgeable answers. There is the range of information from the acute and exact information derived from (untainted) scientific research extending to that of people that seem to have seemingly first-hand knowledge derived from their own personal (time-based) experiences. Only unbiased scientific research can truly give one the correct answer to the question..."are hand-made (glazed) ceramics safe for use in fish aquariums"... if all the parameters one is concerned about are indeed included in the research (ie., species included, type of clays/glazes, durability of the specific ceramic/glaze of the item, fresh vs salt water, tolerance limits of specific contaminants possible from the specific glaze, pH of water environment, general life expectancy of the species, etc.). Not to downplay the input of other participants contributing to this discussion that have personally made 'glazed aquarium ornamentation' for their fishes, but even having done so with no outward signs of negligent effects from their fish after a few years, still does not answer the question posed. A case in point... my father smoked cigarettes for 40+ years and I never recall him exhibiting any outward signs of it having an ill effect on his health. So at any point during those 40+ years if one had asked me '... is cigarette smoking an activity harmful towards human health?'... I could use his case as a case that it wasn't. Any time during the ensuing decades from his first cigarette experience, my support favoring this argument (based on first-hand time-based experience) would be valid. However after these 40+ years he (suddenly) begins having all kinds of respiratory and throat problems associated with this unhealthy addiction. So in retrospect, I would have to say that now my first-hand time-based experience tells me that there are negative (accumulative) health effects to tobacco use. The actual fact was that it was inherently unhealthy during all those 40+ years, even when he displayed no ill effects. So to answer the question.... ' are home made (glazed) ceramics safe for fish in an aquarium?' My reflection on this would lead me to believe that there has unequivocally been no research done to ascertain the truth in this matter as the parameters seem much too expansive and as research is expensive I personally see no payoff (the capitalist support mechanism for the research) that could be derived from such a study. Bottom line... if you are truly concerned for your fishes health & safety and are truly not willing to risk any additional chances against their health, I think the highest fired (non-glazed) clay body with the lowest possible absorption rate, as I mentioned earlier, makes better sense. However, if one assumes some kind of moral judgement as that... then other aspects need also be addressed with concerns of the total environmental control over a subjected species. Is the commercially packaged fish food going into their regular diet really the food that the species naturally eats in the wild or is it just what the profit based 'industry' sells, which may or may not have been researched in regards to actual health impact of that species? The agri-business food industry itself has shown that the concerns are more about profit than nutrition/health, and that is in regards to the food packaged for us humans. Should we look at other environmental aspects as well ...such as the relatively small and enclosed artificial environment that the species is contained within and any affect that may have on the individuals or the group? At what point do we give up our true concerns for a species regarding what is good for them and decide that their concerns aren't as important as what we desire? They are held in captivity solely for our benefit and amusement, not for their health and enjoyment of life, so how much genuine concern does one really need to show? Moral dilemmas about best welfare are generally not a consideration when one species subjects itself over another species/race, for its own purposes. People have and will possibly always maintain their own limits of what they feel are best for others (pets included). So it goes for having 'dominion over....!' And it seemed like such an innocuous simple question posed..... Link to comment Share on other sites More sharing options...
Guest JBaymore Posted March 9, 2012 Report Share Posted March 9, 2012 Not to downplay the input of other participants contributing to this discussion that have personally made 'glazed aquarium ornamentation' for their fishes, but even having done so with no outward signs of negligent effects from their fish after a few years, still does not answer the question posed. A case in point... my father smoked cigarettes for 40+ years and I never recall him exhibiting any outward signs of it having an ill effect on his health. So at any point during those 40+ years if one had asked me '... is cigarette smoking an activity harmful towards human health?'... I could use his case as a case that it wasn't. Any time during the ensuing decades from his first cigarette experience, my support favoring this argument (based on first-hand time-based experience) would be valid. However after these 40+ years he (suddenly) begins having all kinds of respiratory and throat problems associated with this unhealthy addiction. So in retrospect, I would have to say that now my first-hand time-based experience tells me that there are negative (accumulative) health effects to tobacco use. The actual fact was that it was inherently unhealthy during all those 40+ years, even when he displayed no ill effects. Excellent example. And the core reason why there are so many "ceramic myths". best, ...................john Link to comment Share on other sites More sharing options...
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