H2o2 is a wonderful substitute for microbes but what no one ever tells us is the half life of h2o2 can be Extremely * short in some cases.
Im so late fir work i got to go out the door now 
But Google “half life of h2o2 in hydroponic solution”.
Sometimes the h2o2 has to be added ever 2-3 days or even everyday.
With a nice perfect sterile system maybe just when doing a refill say once a week, but sometimes it needs to be added more often to keep actively working 