uneven development

Vigorous agitation

Five to seven inversions in 5 seconds is Kodak's recommended agitation procedure for small invertible tanks. See page 3 of 6 in the following link to Kodak's PDF file on their web site:

http://www.kodak.com/global/en/professional/support/techPubs/aj3/aj3.pdf

I always had more trouble with uniform development before agitating vigorously as Kodak recommends.