You have to know that one cubic foot of water weighs 62.4 pounds.
You also have to know that there are 12 inches in one foot.
(12 inches x 12 inches x 12 inches) = (1 ft x 1 ft x 1 ft) = 1 cubic foot. The water weighs 62.4 pounds.
Fish Oil has a specific gravity of .92. Therefore, if a gallon of water weighs 8.64 lbs, standardized fish oil weighs 7.69 lbs.
A gallon of water weighs about 8.34 pounds. If you have a good sized bucket with a gallon of water in it and you put a 5-pound fish in the bucket, you'll have a bucket that weighs about 13.34 pounds (plus the weight of the bucket). That's as long as the bucket doesn't overflow. The fish will (usually) be neutrally bouyant in the water, and it will be essentially weightless in that water. But its weight will add to that of the water in the bucket. No, it won't weigh 15 pounds, but it will weigh in as suggested. However, the weight of the water itself will not change.
20 pounds
The clownfish weighs only a few grams!
it weighs about 5 pounds. I think
Call the unknown weight of the fish "x". In that case, the statement can be converted into an equation as follows:x = 5 + (1/2)x If you solve this for "x", you get the weight of the fish. (The answer is 10 pounds.)
10.34
If there is no overflow of water, then the container's over-all weight goes up by the weight of the fish. The weight of the water itself doesn't change.
If the fish does not struggle (it would have to be dead not to) and above water, then you can measure a spring scale.
If the tank is actually filled to the brim (tanks never are) the water would weigh 8.35lbs x 30gallons which is 250.5 lbs. To obtain an accurate total weight you would have to add in the weight of the sand/gravel substrate, and the rocks (decore) and the weight of the empty tank. Then you would subtract the weight of the top 1 inch or so that is always left empty.
Yes, fish do add weight to the overall weight of the water in a pond. This is because the fish has mass, which adds to the mass of the water. As the fish swims around in the pond, it displaces the water in the pond, which adds to the overall weight of the water in the pond. Furthermore, when a fish excretes waste or urine, it adds to the overall weight of the water in the pond. The additional organic matter in the water, such as food particles and other organic materials, also add to the overall weight of the water in the pond.
10.34