Those dimensions are closer to 25 gallons
1. It depends on what kind of water you use. The active substrates lower the ph of the water that is required for most caridina species
2. Stuff like aquasoil will deplete over time but how long they last depends on factors like the water you use and how hard it has to work to lower ph
3. Keeping your parameters steady is the overall must when you want to breed in large numbers. Having surfaces for microfauna and bacteria for the adult and baby shrimps to forage on would also help
1. It depends on what kind of water you use. The active substrates lower the ph of the water that is required for most caridina species
2. Stuff like aquasoil will deplete over time but how long they last depends on factors like the water you use and how hard it has to work to lower ph
3. Keeping your parameters steady is the overall must when you want to breed in large numbers. Having surfaces for microfauna and bacteria for the adult and baby shrimps to forage on would also help