Constant lido::MINIMUM_STAKE_ACCOUNT_BALANCE

pub const MINIMUM_STAKE_ACCOUNT_BALANCE: Lamports;

The minimum amount to put in a stake account (1 SOL).

For stake accounts, there is a minimum balance for the account to be rent-exempt, that depends on the size of the stake program’s stake state struct. But aside from this minimum, in order to merge two stake accounts, their credits_observed must match. If the rewards received is less than a single Lamport, then credits_observed will not be updated, and then the stake account cannot be merged into a different stake account. Because we need to be able to merge stake accounts, we also need to make sure that they contain enough stake that they will earn at least one lamport per epoch. 1 SOL should be sufficient for that.