Did not mean to come off as "aggressive" .. sorry about that.
Add enough bleach to get the FC up around 10ppm (does not need to be exact) ... then you need to let it circulate for an hour and test the FC level you acheived. That will be the number you compare to in the morning.
Add enough bleach to get the FC up around 10ppm (does not need to be exact) ... then you need to let it circulate for an hour and test the FC level you acheived. That will be the number you compare to in the morning.