I want to keep them in a 10 gallon after it's been setup and cycled with a 3:1 female:male ratio. I plan on using a sponge filter and no heater (my house gets down to around 60 degrees Fahrenheit or 15.5 Celsius so I'm not sure if I can get away without one). I plan on having moss and/or a mop for the eggs. Can I just leave the eggs in the aquarium to hatch?