Quite interesting. I suppose you use the needle point screens to separate the non breeding fish? I have not seen any needle point screens with small enough holes to keep 10 days old fry in with their mom.
An angelfish breeder friend of mine uses a piece of egg crate (the kind sold in the lighting section of Home Depot) with two pieces of garden hose with a slit cut into it to secure the egg crate divider in place. Works like a charm for separating grown up's.
Last night I had to separate my trifasciata male from the mama and the babies. I used an ordinary tank divider that I bought from LFS. However, I must not have put one side of the divider snuggly against the glass since a few fry kept showing up on the other side of the divider. I tried to reposition the divider but small gravels kept getting in the way.
Is there any easy way to get a divider installed in a tank with gravels without creating a small gap?