The size_frac_low and size_frac_up should be the other way round (in the water_sampling.csv).
When size_frac is 3-200 then size_frac_low should be 3 and size_frac_up should be 200.
Also, size_frac is 0.2-3 then size_frac_low should be 0.2 and size_frac_up should be 3.
Now it's the other way round.
The size_frac_low and size_frac_up should be the other way round (in the water_sampling.csv). When size_frac is 3-200 then size_frac_low should be 3 and size_frac_up should be 200. Also, size_frac is 0.2-3 then size_frac_low should be 0.2 and size_frac_up should be 3. Now it's the other way round.
@melinalou