Backyard Aquaponics
A place to discuss aquaponics

Slows the fish down really well!
They are like fruits afterwards and just need picking.

I'm not a terrorist and don't fish like that but it is used all over the world for food fishing or catching stunned fish for aquarium trade.

Round tanks are really nice for the fish, but can cause problems in harvest.

You can catch them if you have a seine as wide and deep as the tank. Put the seine in the middle, with both ends together. Pull the ends to the edge of tank (assuming the ends of the seine are wrapped around poles or sticks). The ends must press against the walls of the tank. It takes two or three people. One person holds each end (pole) of the seine and pulls in opposite directions until they almost meet. At that point, if the bottom of the seine is weighted, the fish should be confined in the smaller space. Next get the third person to capture the fish with a dip net.

I have seen rigid wooden or metal framed crowders that have hardware cloth or other metal mesh attached. These usually pivot at the radius point. So they work like above seine but you don't have to worry about a flopping net, or the fish getting under easily. This type of thing wouldn't be hard to make of wood and wire with a couple hinges.

I really make sound easier than it is. And some species are very difficult to seine. The Tilapia will turn on their sides and scoot under the net or just jump over the top. Catfish aren't so bad, except for the spines catching in the net.

Probably don't have time for all that. You could possibly contain the new fish in a big wire box of some sort, or net box (hapa) in the same tank. Until you have a good way to catch fish.

Forgot to mention electrofishing. In the US its called telephoning if done for illegal fish harvest. Yet fisheries biologist have units that run current in the water, fish become paralyzed temporarily and are easy to net. DIY would be risky.

I suppose you could unplugg every thing, put on rubber boots and drop an old toaster into your tank. Just kidding. Please don't try this.

A stun gun hooked to a wire at each end of the tank?

3-10 volts with in a couple feet of the fish should stun them. Thats what we used to do a survey of a local pond back when i was in high school worked wonders

There is an easier way
Get a deep recycling bin from the B shop, drill lots of 6mm holes in the bottom, glue(hot glue gun) 75mm slabs of polystyrene from a fruit box on the sides and end, enough to make it float so its 3/4 submerged.
Put the silvers in that and feed them until they grow a bit. They get the water from the fishpond and their waste adds to the total, but they remain seperate so they survive. Easy and you can do it all with your clothes on
cheers
Rodney

Rodney post a photo of your floating duckweed tank

there you go.

Hi Milne
here's my floating tank which now contains some goldies which were scaring the fingerlings away from the food
cheers
Rodney

As we say in MS. "There is more than one way to skin a cat."

Thank you, jdphish. I reckon your method will suit me when I harvest Silvers from the swimming pool.

its not really my idea, its been done for decades in US federal fish hatcheries.

lol i think that was ment as... BAM you got it set not litteral dynamite lol like Mic Dundee lol