Want to install a composting toilet upstairs or in a basement? You can! The best solution for installation below/above the ground floor is a self-contained zero leachate system.
Additives help you maintain microbial activity within the pile, speed up decomposition, balance out pH levels, prevent fly strike, negate damaging effects of pharmaceuticals on the compost, and generally prevent problems from arising.
Composting toilets are designed to keep flies away, and with proper maintenance flies shouldn't be a problem. If, however, you've found flies buzzing around your toilet, you need to deal with them sooner rather than later.