The 1 acre plot is the sampling unit and the experimental unit. The plates or frames are the sampling and experimental unit. Plant or leaf is both the sampling and experimental unit. Aquaria or leaf is both the sampling and experimental unit. Plot is the experimental unit and plant within plot is the sampling unit.
Aquaria is the experimental and sampling unit.
Aquaria are the experimental and sampling unit. The Fields are the blocks, the plots are the experimental error and the sub-plots are the sampling unit.