Another topic of hot debate.
According to Jackerspackle, beneficial microbes will develop in soil and in hydroponic systems. These overpopulate and directly attack diseases such as pythium and fusarium. They also convert the ammoniacal nitrogen in some chemical ferts to nitrates. However, the use peroxide or chlorine, will kill these microbes, increasing the possibility that what is to be avoided will occur.
Wormgod Erliquin comments that H2O2 appears as a curative additive for plants in stress. Plants in well designed and well managed grow rooms should NOT experience stress. Maybe those that see "benefits" of H202 in their grow are those that don't have optimum artificial propagation structures and management. Others use H202 only for helping plants suffering from root disease symptoms, and will only use it for that purpose.
On the other side of the issue, MisterIto contends that hydrogen peroxide is beneficial as an addition to nutrient feeding programs at all times. It feeds the good aerobic bacteria and kills the bad anaerobic bacteria. It also introduces free radical oxygen atoms which oxidize elements, making them more available for the roots to assimilate.