I have two houseplants in tapered pots, not sure if they are clay or fibre pots, wider at top than bottom. Is there a way to ascertain if the plant is receiving the water and nutrients it needs?
Tapered pots shouldn’t be a problem for your houseplants. I would recommend a good quality potting soil, that holds moisture. Water once a week, and every other week you might want to apply an all purpose fertilizer at half strength. However, it is best to stop fertilizing from October to February to allow the plants to rest.
Here is a good article – Watering Houseplants by North Carolina’s State University Extension https://www.ces.ncsu.edu/depts/hort/consumer/quickref/houseplants/watering.html
… and a link to our own Gardening Guide: Beginner’s Guide to Growing Houseplants