Hi,
miker thanks for all your help.
I have attached plants to pebble with a plastic cable tie and buried them in gravel while the tank was half full (just did
water change).
With the plants I want to float on the surface at a specific place, I have used 2 pieces of
driftwood and created a corner (L shape) on the surface by tying them to the top of my tank using longer plastic cable tie.
The plants stay floating within that area without "flying" all over even with the strong water movement.
Thanks Fishlore!