lead will not hurt the water or the plants. only if you file it under the water or eat the lead will it hurt you. lead does not let off toxic chemicals in to water just sitting there. lead is heavier then water and sinks even the smallest of peices. alot of old glasses are made of lead glass. if it was toxic to water they wouldnt let us fish with them. or shot bullets made of them. the only reason they make you us steel shot to shoot water fowl is cause they eat it off the bottom of the lake river it hurts them. but lead is costly and i would us something else.
So much not right with this post.
1) Lead in the presence of air andor moisture does corrode to yield the oxide/carbonate. This will react with chloride in the water and the mild acid broth that is a good hydroponic solution. The lead is mobile in the plant and will create measurable contamination of the bud. One of the reasons lead is such a persistent problem in human environments, outdoor and in- , is because it's mobile and rather soluble in the sorts of salts you'll find it making.
2) Old lead crystal is no longer recommended for drinking, and absolutley a no-no for daily use. A glass of wine in nice crystal will typically pick up 0.2 ppm lead (at or past the currently recognized safe limit), and store the wine in lead glass for some weeks,and 20 ppm lead (aiee!) is not uncommon. Lead crystal is up to 25% lead oxide added to a glass melt.
Count on a phase-out of lead fishing weights ... they cause the same problem as the lead shot that poisons foraging waterfowl.
Someone else suggested brass. This could easily introduce toxic levels of copper and zinc (and lead! Most brass is leaded.) to a hydro solution. Copper and zinc have rather narrow safety/effectiveness margins; this is why copper and brass plumbing is sort of a universal Bad Idea for handling food-grade liquids, and let's face it; we want our bud to be at LEAST food-grade. Jmo ... but an informed opinion. cn