Just be sure to use a mini pump directly pushing water in or out of the little tank. Water will not naturally flow through the mesh enough. This is a fine cheep way to seperate tanks, and if you want to switch up latter you have 2 tanks
But, something tells me you cant get the tank large enough to put a 20 in ;p
It would look cool if u got a 20g with like 30 neons and a powerhead in it and put it inside a like 135g+ with preditors. they would constantly be attacking the 20g to eat the fish
it would be funny to watch a giant fish raming itself into the glass thinking there nothing there
wake up nemo you shouldnt sleep upside down silly upside down nemo wake up wake up WAKE UP OH MY GOD NEMOS DEAD WHHHHHHHHHHHHHHHHHHHHHAAAAAAAAAAAAAAAAAAAAA
Im sorry but the whole idea is ludricous, that poor knofe is liable to do himself some serious harm, especailly if he gets himself caught on the edge of the little tank!
knife fish tend to get really aggressive and a largish one could tangle up the net, pull it off or worse case tangle itself up in the net.
Dividers DONT work nor do floating breeding traps my clown knives could get in and out of fort knox if they wanted to, especially if tetras are involved...........