Join Date: Jun 2013
Location: Toronto ON Canada
For the same number/size of fish, bio load is the same with same feeding, regardless of tank size or amount of water. You get the same amount of ammonia/nitrite/nitrate. Good thing with larger tank is that PPM is lower. In your 120g ammonia is barely registered, probably not much harm to the fish, how much I don't know. Yet it's the same amount, to support the same size bacteria population. Your tank will eventually be cycled, with ease. You can then add more fish, slowly.