By the way, you can put peroxide undiluted into the plants for fungus gnats. Â Not everyday, not like you are watering. Â But it's already a very weak solution.
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Anytime you spray a soap product on a leaf, you need to follow it up with a plain water spray. Â If you coat the plant's leaves, you are clogging the stomata, and interfering with proper respiration. (yes, plants breathe) Â In short, you are suffocating your plants. Â Had they been outdoors under the sun, you would have seen this happen on an accelerated timeline.
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You will probably get new leaves, as it's doubtful that you've killed the plants. Â But next time you spray with soap, leave it on the plant for 20 minutes, and then give a moderate pressure spray of straight water, to rinse the soap from the leaves.
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If you are trying to grow plants indoors, you need to be prepared in advance for these sort of battles. Â At the very least, you need to have a shower or wash basin, where you can do spray downs for pests.