A density of about 5 grams comes in a teaspoon and as you require 400 mg which means you need 0.4 grams which is equal to 12th part of a teaspoon. If I've done my math correctly, that's 1/4 teaspoon per 3 gallons water. This mixture of powder tetracycline is used in cold water for treating hens with CRD. Please follow the dosing instructions on your package; I'm not a veterinarian.
0.16 measuring spoons of turmeric has been present in 500mg of turmeric in standard measuring spoons.
This cannot be sensibly answered. A milliliter (mL or ml) is a measure of volume, grams is a measure of weight or mass.
That is 4 teaspoons
400 mg = 0.4 g
400 mg = 0.014109 oz
400
to measure stuff
A kitchen scale or measuring spoons are commonly used to accurately measure salt in recipes. Alternatively, a salt spoon can also be used for a more precise measurement of smaller quantities.
400 IU of vitamin D is equivalent to 10 micrograms (mcg) or 0.01 milligrams (mg).
There are 0.4 grams in 400 mg, and 1 gram is equivalent to 0.001 kg. Therefore, 400 mg is equal to 0.4 grams or 0.0004 kg.
to measure stuff
A single dose of cefixime 400 mg is not equal to 200 mg twice a day.