9,510.19 Gallons
A gram is the mass of 1 mL of water. Imagine a cube, each side 1 cm in length. Fill up that cube with water. That much water weighs one gram. A rough estimate is that one gram is about the weight of a standard paper clip.
More information is needed in order to answer this question. The size of the pond, preferably in square meters.
1/2 cup
Crayfish are very good at getting out, so it's best not to fill a tank to the top.
About 18,000 gallons.
5300 gallons
About enough to fill a 1 meter cube
120 Kpa
if it's 4 ft deep 21,139.948 gal.
1 oz of water
I cup