Hi mate, how big is the tank? I did a 60 x 30 x 30 carpet and used 7 pots and took almost 2 days. It was well worth it itll my boss ruined it with loaches and all kinds
The more you add the faster it will carpet.
Is it a brand new substrate? if not then no doubt you have a little to much detritus in the substrate and yes, it isn't a good thing.
You will get a load of "floaters" lol but just put them back in the substrate. Patients is the key with HC, i've just ripped out the "little mountain" HC and i've replanted it and it isn't moving as fast as i'd like. I've heard it NO3 hungry so you can adjust your dosing accordingly.
Man, you guys are patient. I really couldn't be bothered to plant stem by stem. I just get clumps of about 2p in size and just push into the substrate. Can normally do the whole width of my 4 footer in less than 10 minutes. After a month it's all filled in and soon after needs redoing again.