SAFE PETRI DISH material to use in aquarium?
I'm looking to get safe petri dishes to use as feeder stations for my shrimp and other bottom feeders.
I know most will just say all are safe to use in the aquarium, but I always want to be extra sure, so I've been researching a bit. I might just be overthinking it, but then again there is conflicting information out there. Remember just because there are no instant noticeable side-effects does not mean it's not harmful.
I have seen most petri dishes are made out of plastic/acrylic, flint glass or borosilicate glass.
I have read plastic/acrylic ones will float in fish tanks so that is no good, plus I hear they release environmental estrogen (at least a problem with frog breeding).
Flint glass is said to be for unheated applications and so it's not very temperature resistant (I think it was mentioned to not use in anything over 70*F, which most aquariums get hotter than, not sure of the effects). And it's made from lead (not sure if that leaches though). Also I hear flint glass is not very chemical resistant (not sure how that is effected by the commonly used chemicals in the aquarium hobby)
Borosilicate/Corning glass seems to be ideal for aquarium use since it is very durable and chemical and temperature resistant. If I remember correctly, I read that Boron (which is what this glass contains) is also toxic (at least in high enough doses, not sure if this leaches either).
Now here's the thing, I was looking at some of the cheap eBay China glass petri dishes. I asked the seller what glass was used and I was told "neutral glass". Only thing I could find through a search was on a Borax website saying it was a pharmaceutical glass which can be engineered to have effects such as altering pH. But that was all I could find. That doesn't mean the ones for sale alter pH, but I don't know how temperature or chemical resistant it is or anything else (basically if it's aquarium safe).
I'm no expert, just did a little digging and hoping someone who does know more can offer some input. I'm not even sure if sellers of "purpose made" shrimp/fish feeding dishes, know what material the dishes they sell are made out of.