Hello Pon...
Once the new plants have 3 to 4 nicely developing leaves, you can clip them from the mother plant. Just clip the mother plant, though. Don't damage the black threads of the new plant. Keep trimming the mother plant, it will eventually die off.
You can attach the new plants to pieces of lava rock or driftwood with long strands of black sewing thread or a thin rubber band works well. No need to plant these in the substrate.
B
Hello again Pon...
I typically wait until I change the tank water to trim any plants. When the water level is low, I take a sharp bladed scissors and clip off the part of the mother plant that holds the new plantlet. There's no other reason to disturb the mother plant.
I use thin thread or a rubber band to attach the new plant to a piece of lava rock and just drop the plant on the substrate. Driftwood is fine too. The wood can be weighed down with a rock or two. I like to float the driftwood for a different look. The thread or rubber band will dissolve in the tank water. By then, the plant has grown into the pores in the lava rock or into the substrate.
Fishing line is fine, but won't dissolve in the tank water in this century. It will likely be covered by algae in time.
B
Pon...
You'll just leave the little bit of the mother plant attached to the plantlet. Then, you can attach the new plant to the lava rock or piece of driftwood. The roots of the plantlet will take in nutrients from the old plant and fish material that dissolve in the water. This is why you don't want to vacuum a tank with live plants. You'll remove nutrients the plants need.
Everything eventually dissolves in the tank water. So, all you need to do is remove and replace half the water every week or two to maintain healthy fish and plants. It's best to leave everything undisturbed when performing a water change. Just remove and replace the water, nothing else. If you disturb the substrate by vacuuming, the result can be cloudy water and possibly damaged plant roots.
Hope this makes sense. If not, I can certainly clarify something.
B
Just brab the new plant down where the roots are and pull it off it shouldn't cause any damage to the original leaf but just be careful when you do it
One question I haven't seen answered yet. Do I need to acclimate plants when transfering to new tanks? Seems like I should, but not sure if its necessary.