Answer: Watering depends partly on what plant you are growing and its preferences, and partly on the potting mix you are using, and partly on the environment where the plant is growing -- is it warm or cool, dry air or humid, is there a lot of air circulation or is it quite still, and partly on the size of the plant in relation to the container.
Unfortunately, a once a week schedule probably is not going to be ideal for all of your plants although it may work well for some of them. Let your plants' performance be your guide.
Aphids can be treated several ways. If there are just a few you may be able to remove them gently by hand or using a cotton swab dipped in rubbing alcohol. Or, you could rinse them off with a spray of tepid water in the sink. Or, you could treat them with commercially formulated insecticidal soap per the label directions.
Aphids tend to attack overly lush new growth such as can happen when plants are overfertilized. However, once aphids appear on indoor plants you may find that they spread from plant to plant due to the artificially enclosed growing area. If you have a badly infected plant you may want to isolate it until you get the aphids under control.
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