Lead anchors
I used to use these, but since most plants root pretty easilly there were only a couple uses I found. Holding down hornwort (which doesn't root), and bending anacharis so it will produce sideshoots. Both cases I used a 'U' shaped piece and a bent heavy nail would have worked too. Now I use a hemostat to push the end of a stem plant down far enough into the gravel that it doesn't move. Sometimes a small rosette plant won't stay and I use 1-2" pebbles to hold it in until the roots take hold.
There are at least 4 lead anchors lost in the substrate in my 20g. Plants grow great, angelfish were fine and corydorus bred in there as well. So I don't think it's as serious a problem as some might suggest. I don't think anyone has done an autopsy on their fish to prove that lead poisoning killed it.
Lead dissolves much faster in a low ph environment than a high ph one. Tap water usually comes at a very high ph so that the lead and copper in the pipes doesn't dissolve into the water.
