a good test hatch for local eggs would be 10 or more IMO. the larger the sample the better you'll know if it's the incubator or you.
and don't count clear eggs against your hatch rates. you have no control over the rooster! if there was a blood ring or any development beyond that, then it was fertile and counts in the final tally.
and don't count clear eggs against your hatch rates. you have no control over the rooster! if there was a blood ring or any development beyond that, then it was fertile and counts in the final tally.