That's a shame.
Have they bred before or are they new to it?
I got them from my friend, who says they had one spawn before.
They're an established pair, but I'm guessing the previous spawns didn't pan out for him given that they were in a 5 gallon, either that or its the same issues here.
Hopefully I'll see another batch soon, they've got an ideal location for it; air sponge, over hanging wood with slate underneath, in a darkened part of the tank.
The tankmates are white clouds, who stick to the other side of the tank where the light is