BushFishRox;1046787; said:metals dont get to build up to toxic levels in lakes and such since they are in a huge volume of water but the home aquarium doesnt even compare to a lake and aquariums just cycle the same water allowing toxins to build up which is why we need to do water changes to lower nitrates and heavy metals are more toxic then nitrates.
Actually it doesn't take much lead to contaminate a large volume... however, lead in ingot form like pellets doesn't generate the tiny free floating particles needed to infiltrate biological systems.
You can't really say "heavy metals are more toxic than nitrates" either... what heavy metals? how much? by what method of exposure? gold is a heavy metal that's not toxic to most organisms... thallium will kill people in tiny doses though. Lots of wild fish eat fishing weights and continue to live just fine.
Anyway, I probably wouldn't keep exposed lead in my aquarium just because there are other ways I'd rather use, but I don't think you'll have a problem. Lots of people use lead to weigh down plants.
