Keep in mind that ammonia is an antiseptic when at strong enough levels, meaning that too much can actually be used to kill bacteria! So it can actually become enough to kill the bacteria that you are growing. But then some details need to be thrown in as to how you are doing the cycle and what end result you want as there are several ways to go.
Old style before we called it a cycle was to simply add fish slow enough to gradually let the bacteria grow to meet the added waste load. Downside of this is that it exposes any fish to that ammonia and they may appear to be okay but actually damaged so that they have shorter, less healthy lives. It was also a very slow, haphazardous process as we guessed at when it was ready to add more fish.
Over time, as we became more used to shipping fish, we wanted to get a bunch of fish shipping in all at one time for saving on shipping, so the "fishless cycle" was developed. With it we add X amount of ammonia from a bottle and watch the levels of ammonia be converted to nitrite and finally nitrate. We change the water and adjust the ammonia added to keep ammonia, nitrite at a moderate level while the two bacteria types grow and then before we add the fish, we do massive water changes to clear the heavy load of nitrate we have built up. Slow and tedious but we are then ready for a massive increase of fish load because we have built a massive bacteria colony.
Planted tanks often go kind of a modified in-between thing that relies on plants and luck as much as anything to hope they get the right amount of bacteria for a reduced load that planted folks often use.
So what is your plan going forward?
I like doing the fully trusted fishless cycle so that I know that my tanks are ready when I add fish but I do it using old media from other tanks which shortens the time due to both bacteria groups being moved in, instead of waiting for them to blow in on the air!
I prefer adding iron by dry ferts as that is one way to know that it is there, where using what is in the sub is not something that I can know as it may be there at first but gone at some point. I much prefer adding it and knowing it is there.
Last edited by PlantedRich; 07-17-2019 at 08:29 PM.