ummm You might have f'ed yourself in the A... sorry to say....H2O2 for Dissolved oxygen is just not efficient, you need airstones. You might have just killed all your roots depending on how much you used.
I used Physan once very very very small amount to try to get rid of some brown algae and my roots went from shiny white to a brown tint then the plants started dying and there was nothing I could do. I did save the basil although it has to completely regrow its root system from scratch all the roots that had turned brown were just dying but alive enough to keep the plant alive long enough to spit out new roots and then those roots took over and all the brown roots kinda just fell away.......
Soooo sorry to say you MIGHT have killed your plants or stunted them until they completely regrow a new root system.....