You're welcome.

Once you have real plants, if planted in substrate, you can occasionally push a frog poo into the substrate near the plant roots for plant food. Once every week or two is fine.

Another good thing to do is to purchase captive bred springtails and/or isopods. They will eat plant debris and frog poo missed. Little housekeepers for your substrate. That is what poison is referring to as a biologically live substrate. Also, some bacteria will grow in the soil that can break down wastes, like in a fish tank. These only apply when using a false bottom though. Moist substrate without a false bottom can actually allow so much bacterial and fungal growth, along with feces and urine in a wet boggy substrate that it can create a toxic waste floor making your babies sick. In nature, the rain provides a constant cleansing which leaches deeper into the earth and the rain runoff will provide a nice new clean floor. A false bottom allows us to have a rinsed under water reservoir to drain soiled water. It is a bit like creating a leach bed of natural filtration through layers of earth like the old sewer systems.