can't change some nfs options

Im not able to change NFS mount options rsize, wsize and timeo from the default. My /etc/fstab has this entry

192.168.10.10:/volume1/Containers /mnt/circe nfs defaults 0 0

This is fine

mount -t nfs -vo remount,rsize=131072 /mnt/circe

This gives me "invalid argument"

mount -t nfs -vo remount,rsize=32768 /mnt/circe

Kernel: 4.15.0-111-generic x86_64 bits: 64 Console: tty 2 Distro: Ubuntu 18.04.4 LTS
mount.nfs: (linux nfs-utils 1.3.3)