you should do pwc
to reduce nh3
which will kill off a lot of the life when it gets off the chart. Too high nh3
does nothing to cultivate bacteria and can easily overwhelm the bacteria currently in the lr
Are you sure you are seeing 5 ppm
? Typically you don't get no3
readings after only 4 days.
I'd try a 30% pwc
and recheck your readings after a couple of hours. If back within 3-5 ppm
then I'd leave it alone unless it goes off the chart again.
It could prolong your cycle time but paying $$$ for dead rock isn't worth it IMO