After you put the beneficial bacteria medicine into the aquarium, now it’s time to breed as many beneficial bacteria as possible. Aside from playing a role in the Aquarium Nitrogen Cycle, beneficial bacteria can fight the bad bacteria that get into the aquarium water. There are many ways to breed beneficial bacteria in the aquarium as follows: – Using bio foam: Buy stone water that comes with Bio Foam Filter. Spreading gravel: Gravel will act like an aquarium water buffer. Using Bio Ring: Bio Ring can be placed in filter canister, sump filter, hang-on filter and submersible water pump.