walls 32 and 33 with passages 34 extending through wall 30 into the hollow interior formed by bottom wall 46 and walls 30 32 and 34 thus liquid may flow into the hollow interior of the flared bottom portion providing increased weight at the bottom of the partition bottom wall 46 extends a distance greater than the thickness of the main body of the partition this increased distance or width of the flared bottom portion coupled with the increased weight of the flared bottom portion provides increased stability of the partition limiting the amount of relative motion if any existing between the partition bottom end and the bottom wall 58 of the tank in order to hold the partition from unacceptable movement the downwardly opening channel 24 fig4 extends over the top end 35 of partition 22 with the downwardly extending legs 46 and 47 being spaced apart a distance greater than the thickness of the top end 35 of the partition allowing only a limited if any movement between the partition and channel 24 while the top end of the partition is depicted as hollow in fig4 the present invention includes a partition that is solid without any internal cavity existing between the downwardly extending opposite side walls of the partition until the partition flares out at bottom end portion 31 partitions 22 and 23 extend in the direction of the longitudinal axis 60 of the tank the downwardly extending channel 24 limits sideways movement of the top end 35 of the partitions relative to the longitudinal axis and the side wall of the tank a plurality of vertically extending strengthening ribs or channels 39 fig3 are formed in the partitions adding to the strength of the partitions a rim is formed at the top end of.