1 US Gallon of water weighs 8.35 lbs. The tank will not be filled to the brim so you can deduct about 0.5 gallons from its maximum capacity. So the weight of the water would be 8.35lbs x 4.50 which is 37.5lbs. You would also have to weigh the tank and other things like lights, cover glass, heater/thermostat, thermometer, filter complete with media, and gravel etc. Everything that you use in the tank must be weighed and added to the water weight to obtain an accurate total weight.
One gallon of water is 8.345404 Lbs.So a 100 gallon tank would have 834.5404 lbs of water.
According to "How much does one gallon of water weigh?", a gallon of water weighs approx 8.35lb. Given that sperm is mostly water, It would weigh approximately 8.35lb.
At 17oC one gallon of water weighs 4.536kg.
About 8.35 pounds.
A gallon of brine weighs more than a gallon of water, but how much more it weighs than a gallon of water depends on how much salt was added to the water.
About 478 lb.
One gallon of water weighs about 8.35 pounds (about 3.8 kilograms).
1 gallon of fresh water is about 8.36 pounds
About 8.35 pounds per US gallon.