I typically make 500 ml batches of ferts at a time, with 40 grams being about the maximum amount of any one chemical involved.
When I bought my inexpensive digital scale I did not buy calibration weights (at $4+ each!), but I did want to calibrate my scale in the weight range of the chemicals I weigh. I calibrate my scale with (and for) pennies! U.S pennies made since 1982 have a mass (weight) of 2.5 grams, four (4) cents weighs 10 grams. U.S. nickels weigh 5.0 grams, four nickels weighs 20 grams. Inexpensive weights and I usually have them in my pocket. Just wanted to share my method with you.
Penny = http://hypertextbook.com/facts/2002/MillicentOkereke.shtml
Nickel = http://wiki.answers.com/Q/How_would_you_measure_the_mass_of_a_nickel
When I bought my inexpensive digital scale I did not buy calibration weights (at $4+ each!), but I did want to calibrate my scale in the weight range of the chemicals I weigh. I calibrate my scale with (and for) pennies! U.S pennies made since 1982 have a mass (weight) of 2.5 grams, four (4) cents weighs 10 grams. U.S. nickels weigh 5.0 grams, four nickels weighs 20 grams. Inexpensive weights and I usually have them in my pocket. Just wanted to share my method with you.
Penny = http://hypertextbook.com/facts/2002/MillicentOkereke.shtml
Nickel = http://wiki.answers.com/Q/How_would_you_measure_the_mass_of_a_nickel