Have you used mason jars to measure?
Ball jars come with cups, ounces, and milliliters molded into the jar.
Mason jars make great measuring “cups”. 1 cup = 1/2 pint jar cups = pint jar 4 cups = quart jar 8 cups = half gallon jar.
12 oz.-Three-quarters Pint
16 oz.- Pint
24 oz. -Pint-and-a-half
32 oz. -Quart
Do you know whereabouts on the quart jar to fill it to for exactly a quart of water? I am making cut flower food and it calls for a quart of water, but about how far above the 800 ml line is it?