Counting and weighing stock in large tanks

[ansihkgt 0]

Hello all,

when adjusting feed it is crucial to have a count of the number of fish in a tank. is there an easier way of counting and weighing 500 or more fish within a tank.

Edited November 9, 2018 by ansihkgt (see edit history)

[ande 848]

Hi ansihkgt

Take a picture, then count the number of fish in the pic, this way the fish is not moving around and can be marked of when counted 

cheers

Edited November 9, 2018 by ande (see edit history)

[ansihkgt 0]

Lol, neeat. I also meant weighing them as well. Title edited.

[Toga 179]

Hi ansihkgt,

I use to catch and weigh a sample number, say 20 fish out of 500... then calculate the average weight and then x 500.

Not only useful for adjusting feed rates, but also very important for assigning simple stocking density, transport density & container qty, medication, compound grow out and so much more.

Cheers
Joe

[ansihkgt 0]

pretty much what i was thinking of doing i have about 700 fish in total. hoping to take weigh 50 and do the math.

Was hoping somebody would have a better way to tackle this.

[kellenw 857]

22 hours ago, Toga said:

Hi ansihkgt,

I use to catch and weigh a sample number, say 20 fish out of 500... then calculate the average weight and then x 500.

Not only useful for adjusting feed rates, but also very important for assigning simple stocking density, transport density & container qty, medication, compound grow out and so much more.

Cheers
Joe

That's always been my approach as well.  It's not going to be perfectly accurate, but it's close enough to give the operator a good sense of the total fish mass in the system.  At the tilapia hatchery, this was an exercise we did about once a month.

[phri 181]

And if you take regular weight counts (maybe 1 x every 10 days) you can follow performance of the animals with regards to total biomass, FCR and SGR.