What are the ideal conditions for beneficial bacteria to live and grow?

As long as the bacteria is getting a steady flow of water and food source which can be left over food from your fish as well as fish waste or decaying food or plants they should survive. These excess nutrients will feed the bacteria. So it is best to keep in a good flow of water throughout your tank to make sure that you did not have me dead spots from lack of water movement. You can use the wave maker ATO (Automatic Top Off Unit) or pumps are power heads and even filters for this.

The temperature of the water generally should be above 55° for ideal conditions and best growth of the nitrifying bacteria.