"Craig Brye" wrote
Does anyone use lead weights to keep stem plants from floating around?

I do.

Are they safe?

Completely. Possibly they are not even made of lead.

I recently saw some in a store, but neglected not to get any.

A wise purchase :-)

I'm sick of constantly having to pull up my stem plants and then
replanting them in the gravel. I have to clip them every 4-5 days
or they'll take over the tank.

The price of success I'm afraid.

I would love to just wrap a lead weight around them and drop them in.

Wrap away. No problem. Different plants require different
approaches. I have a mixture of :

1. Potted - Pennywort
2. Weighted - Bacopa
3. Planted - Hygro, Dwarf Sword, most others
4. Attached - Anubias, java fern

A weekly trim and a monthly 'hack back' keeps mine looking dandy.
Regards

--
Graham Ramsay
Blairgowrie (UK)
www.ibrox.freeserve.co.uk/aquarium.htm