I bought some flexible aquarium barriers and divided the 10-gallon aquarium into three volumes that can each get the benefit of its filter and heater. One is for baby fish, one for the red & black guppies, and one for the blue guppies. I had to tilt the dragon-shaped piece of wood up on one end.
A female guppy floats in the maternity hutch or breeding box, as it’s called. Her fry fall through the slots to the protected area below, where she can’t go. If she decides to eat one, she sucks it in in an instant. The fry practise darting away if they can.
I tested the water in my aquaria, and it’s very hard, which is not good for the fish. My reading indicates that wood softens the water, so I bought a piece of decorative driftwood for the 10-gallon aquarium. It’s shaped vaguely like a dragon with a pointed snout.