TwoTankAmin
Fish Connoisseur
Once you begin adding slowly rather than all at once after a fishless cycle, you begin to lose the advantage of being able to stock fully. At the outset you have a full colony of bacteria intended to support a full load of fish. If you change things at his stage and add fish slowly, you lose the advantage. Instead of the benefit of full stocking allowed by cycling fishlessly, you convert things back to the more traditional method and then must add gradually.
