Here's some snippets of my conversation with my guy:
Me: "someone posted that there is a thread on R2R saying that ABS and PLA are both safe. I'm curious, what chemicals did you test for?"
Him: "A lot; I don't want to give away all of my insider information as I spent a ton to test and a lot of time, and the industry is no where near caught up to what I believe I know. I can tell you this affirmative, PLA Is not safe"
Me: "So is it one of those things like vinyl hose where technically it's not reef safe but people still use it and most don't have problems? Or at least, none they can easily pinpoint because it's so subtle. I'm guessing some materials are worse than others"
Him: "I can almost guarantee you will notice the problems after six months. But yes, people put deer skulls and things in tanks, and that's a no no too. I guess it's whether you care or not"
Me: "Even with regular water changes and carbon filtration, etc?"
Him: "Two guys on [local group] had
complete kill offs from whatever the guy sold at the last swap. My best guess was PLA. Cheap guppies didn't make it in any of my tests past 5 months. With by weekly 20% change."
* emphasis added. The items sold were 3D printed frag plugs and frag racks.
What I can tell you is that "any of my tests" was all inclusive of
all 3D printed materials except for one specific material and even then only one specific color, and I have been asked not to reveal what that material is, he's a friend so I have to respect that. But honestly, it's totally killing me on the scruples factor because I'm not the kind of person to hang on to information that I consider critical knowledge. Even if it is a competitor, I would prefer to tell them that the material they are using is not reef safe (even if it's only remotely) rather than sit back and eat popcorn because if it means that even one person avoids tank problems because of this, then I've done that person a service without them even knowing.
I think my friend's point is valid, so if anyone has any long term testing that contradict his findings, I'm sure he would be interested to know about it. I did a cursory search and couldn't find much.
I've had a 3D printed overflow box in my tank for about 3 years now.
I'm sure you're not the only one that has not had problems, and since I haven't been able to find an outpouring of threads saying that all their stuff died because of the 3D printed material they put in their tank, this tells me that if there are issues, they are probably very subtle. So I'm not clanging the alarm bell and saying don't use any 3D printed material in a reef tank. I'm just saying that it appears to me to be a risk potential that hasn't really been fully evaluated