Why does HC only come in seedlings? They have to start out as seeds somewhere. I want to put some on a flat piece of wood. I got a piece like that but it has Hair algae on it. It is sitting in a bucket of water. Been treating with 2x Excel but really don't want to add those spores to my main tank even if the Excel works I am afraid I would miss killing some. Could that happen?

HC is a stem plant, so the easiest way, by far, to propagate it is with cuttings. Growing plants from seeds is more work than most people would want to do.

If you want to disinfect the wood dose Excel full strength on the wood and let it sit for a few minutes, nothing will survive that.

When the hair algae looks dead is there a chance that there are some spores that will come back? I poured Excel on the wood, the HC doesn't seem to have suffered but the hair algae turned white. I know I am being picky over this silly pieced of wood with HC, Its just that I like it.
I have some HC that was sent to me. It was grown in a tub this summer. The mate is so thick with sod still attached it is hard to see little plantlets. The mat is so thick it sinks on its own.

When you are starting or get plants for future tanks do you set up a whole tank system? Heat, Excel, Micro's and macro's, and filtration? I have left plants on the counter with just water to cover and Excel with no direct light. I do 50% weekly WC. They will stay that way for weeks and weeks sometimes till I figure where to put them in my tank. Is this the way not to do it?

I may ask strange questions, but you are the only Forum that will answer them. So thanks for that.