I forgot to add... To open channels on a private network you can do it also with 0-fee.

0-confirmation channel is a Lightning channel that is not yet fully confirmed on the Bitcoin blockchain. This means that the funds in the channel are not yet completely secure, but they are still very likely to be safe and usable over the LN. Peers can still make payments between them using that "unconfirmed" channel.

Read more about 0-conf channels here: https://lightningdevkit.org/blog/zero-confirmation-channels/