I am able to get a hold of the fluval edge 23L for £62
My Cory Julii have recently be active with their egg laying and I already have a few fry in a cheap goldfish bowl.
My plan was to setup the fluval edge with plants, sand and driftwood and place the newly hatched fry and eggs into it. Basically a fully functioning aquarium but for fry only (and possibly a couple of cherry shrimp as a clean up crew)
Will this be good for them? Or will it be worse than going for an empty tank.
planted tanks with sand and a healthy microbiological flora will be very good for young corys. not sure about a all new tank though. it will take some time to circle it and to get stable enough.
if you are going to have lots of fry, 23l might be a little too small. if u can get a bigger one, e.g. 45-60L you might be better of in the longterm.
While it will be a new tank, everything including the water will be coming from the main tank (Probally just before a water change). I also have extra sponge in the main filter that can be transplanted into fluval edge filter.
I moved 17 Cory fry (oldest 2 weeks, youngest 1 day) out of their bowl and into the new tank today.
Tank was filled with water from the main tank and the tiny filter media was put in the bucket of water used to washout the sponge media on the main tank.
I plan on getting a couple of cherry shrimp tomorrow to help keep uneaten food down.
Very nice! ... (nicer than a lot of my permanent tanks. )
By the way - I don't recall if anyone mentioned this before, but if in the future you ever need to transfer the really small fry (or loose eggs) again, and you're afraid that netting them might hurt them, a turkey baster works really well.
I always wondered if it wasn't much of a hassle to skape and maintain a tank with that small of an opening?
Corydoras like to "breath" air from the water surface. Not sure if they will find the open area to get some air or just crash into the top glas. You better keep an eye on your corys trying to get some air in there. You might have to lower the waterlevel, though this might ruin the purpose of this specific tank.
Wasn't too much of a hastle setting up through the opening, might be a bit tricky when the cleaning the mess from the sand, especially now everything is in place. Guess time will tell .
There is a 3 to 4 mm gap between the waterline and tank top, it did look good when filled to the top (doesn't look too bad with the gap either) but I'll save that for when the fry move into the main tank.
The fry seem a lot more active in there, the oldest was quite active when I turned the lights out, in their old bowman I hardly saw them.
Very nice! ... (nicer than a lot of my permanent tanks. 
)
enjoy watching them!