Chow_13answered grow question 4 years ago With your next watering you can add tbsp of hydrogen peroxide(3%) per liter of water. This will help kill any bad(and good) bacteria and also provide additional oxygen to the roots. Usually over watering can cause root rot because the roots cant get oxygen. Then they become week and get attacked by bad bacteria. Even doing a small dose( 1/4 cup) before your next watering will help the roots recover. 3% is usually the maximum recommended. To be safe I would do a 1:1 with water
Good luck and happy growing.