Another update -

You know how I started with 3 water plants? Well 2 of them sort of have a "bulb" or root mass, but the 3rd one does not.

It was called "frill" in Petsmart. I don't know the real name. I googled around and it looks like other people say it's a type of Myriophyllum.

Anyway this plant has 5 or 6 stems, with frilly leaves, and no roots that I can see. I didn't notice this at first, but the plant came with about a 6 inch long, 1/4 inch wide strip of lead wrapped around the stems, holding them together and keeping it on the bottom.

Is it possible that having this lead in the water could poison and kill the fish? Or is lead OK in the fish tank?

The lead looked pretty oxidized and covered with black junk. All in all, the water plants at Petsmart don't seem in very good condition or healthy.

I spoke with an employee there, who seemed really knowledgeable (cute too!). She said the reason their plants are in poor shape is because they don't have any fish to supply their nutrient needs

Anyway... Just to be safe, and following some advice I read online about this plant, I removed the lead strip and separated the strands, and planted each one separately around the tank, instead of all in a bunch. I read somewhere that the plant would thrive better this way than in a bunch.

I'd appreciate any advice! The aquarium looks nice plant-wise but I don't want to keep having fish die :( I'm down to 1 fish!