Sorry for being light on the details already had a a thread about my cycle. Long story short: cycling for 7 weeks, had massive white hair algae bloom. Most was sucked into my filter, decomposing and has been releasing ammonia in addition to the single dose I placed originally at the start.
I understand the concepts behind the nitrogen cycle. I assume I'm done or near done because at one point last week I was able to get all the readings low enough to measure. Nitrites would rise off the chart and nitrates would rise over 10ppm each day.
My tank finally started producing less ammonia to a point where the bacteria are now able to convert an additional 4ppm of ammonia along with whatever algae may still be decomposing. However like every fishless cycle article states, including the ones here, the nitrite to nitrate bacteria are slightly behind the ammonia converting ones since there weren't nitrites to consume at the start of the cycle. The guides also state that there is no problem doing PWC
during a cycle to lower nitrites and nitrates down to readable levels as there are a negligible amount of BB in the water itself.
Even though I still read nitrites in my water column, my reasoning leads me to believe that if I'm adding over 10ppm of nitrAtes every day, I must be converting that much ammonia and nitrItes at least (you can't create something from nothing). But since there is more ammonia converting BB, there is a backup at the nitrite stage of the cycle.
In addition, my original question stems from reading other user methods of doing PWC
with a python. Some dose the full dose in the beginning. Some dose half first then half during. Others dose after. Even though there is BB on every surface in the tank, most of it is in your filter. I've read of users dumping untreated water into their tanks and not realizing it until later with no negative effects on their biofilter. I wouldn't be doing this obviously as the filter is off during PWCs.
Sorry for any typos, I'm using my phone. Crazy lightning storm keeps knocking the power out!