Building net box for growing fish in the main display?

[Omrit]

Recently I was growing fish for my 300 gallon African cichlid tank and the 40 gallon I was growing them in was getting cramped but they were not ready to be with my big fish(in my opinion). So I cut a hole in some green house panels and glued a screen over it to make a divider that allowed water to pass through. After I installed it giving them 1/3 of the 300 I started growing them there. Being in such a large body of water they grew fast and when I removed the divider my fish were already used to them, there wasn't even a bit of drama.

I was thinking of a way to do this on a smaller scale and I thought about making a frame that sits near the top of the tank with a net fitted around it. Like those guppy breeder boxes people place pregnant guppies in right before they drop their fry just a fair bit larger than those. I could grow some fish in it and whenever I get a new large cichlid I can use it to acclimate them. Is there any reason this wouldn't work? I was very happy with my divider and this sounds even better, but I also have not seen anyone use such a method hence I ask.

 

[qldmick]

I made this one,


This other ones from a Koi/pond supplier, could help with ideas

 

[danotaylor]

Amazon has all kinds of kits to build custom dividers. I bought 1 for $40 if o remember correctly and made a divider for my 500gal tank 34”W x 29”H. Very easy to put together. Easy to cut to customize exact fit. All suction holders come with the kit. 11.75” squares that connect together. I could custom build 1 for any where near that price
I don’t have a clear pic of the 500gal cause it has a black background, but there was enough pieces leftover to make a divider for my 125gal as well. Easy to see against blue background.

 

[wednesday13]

very common for people who breed stingrays to use “pup boxes”…. I personally used and like rubbermaid containers floating or tied up to the tank braces. Drill whatever holes you wish and place in the current. The better way to run them is use an airlifter to pump fresh water into the tub and have it exit through holes on the other side of the container. The clear Rubbermaid totes are nice and almost as clear as the glass so u can still view everything as normal. Heres one i used yrs ago… super beneficial like u mention to have the fish in a larger system with better water

 

[jjohnwm]

As soon as I read this thread I thought immediately of the set-up that wednesday13 shows above. I've done this many times with excellent success; can't tell the details in that pic, but it looks like mine, where the airlift shown protrudes through a hole cut near the bottom of the floating box and draws water up and into the box. The water then flows out through holes drilled in the other end, or through a window cut out and then covered with a sheet of screen. This works beautifully, with a constant steady stream of water running through the box. It also allows the box to be clipped or attached solidly in the desired location with no fear of it flipping or sinking too far. Best of all, done this way it lets you use the cover that came with the box to contain jumpers.

Depending upon the size and species, it's a good idea to cover the mouth of the airlift with a piece of screen to keep more adventurous fish from swimming down the airlift and escaping into the main tank.

If you don't want to put this much work into a temporary structure, you can skip the airlift and just drill a bunch of holes...a lot of holes!... in the sides and bottom of the box. These allow a passive exchange of water between the box and main tank, but you can also gently lift the box almost out of the water and then allow it to settle back down several times daily. This flushes out all the waste and debris and changes most of the water all at once. If you go this route, the box has to be left free-floating rather than fixed in place.

If you decide to build the mesh bag type with an internal frame, make sure the mesh is stretched fairly taut on the frame. If you leave it too loose and baggy, fish in the tank can grab one of the smaller ones in the bag right through the mesh. They won't be eaten, but they can be killed and thoroughly squashed, to be found later by you. Don't ask how I know...

 

[HarleyK]

wednesday13 That's brilliant. I've never kept rays... why do you want to separate out the pups?

 

[wednesday13]

wednesday13 That's brilliant. I've never kept rays... why do you want to separate out the pups?

Need somewhere to stash them when there born basically. The parents even will chew on and kill them. Its best to keep them in the water they were born in for a while as well IMO. The boxes really do work out great tho being in a larger system. The same size tank on its own could not hold 6-12 pups and stay clean/stable. The small area helps small fish find food easy. I kept a "growout tub" like this in alot of my tanks for alot of years. They come in handy and allow you to buy more fish when you dont have tank space as well . No fear of setting up a new tank thats uncycled is another positve in a pinch if someone is getting beat up or a fish comes in smaller than expected when ordering. The one pictured was specifically for a small lung fish that could have drown in too deep of water. he lived in that tub until 18-20".