Should I add coffee grounds to the water when watering house plants?

No it is to acidic and you will risk burning out the roots

Hi Lynn, Here's a link that explains how and when to use coffee grounds! https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/diluted-coffee-for-plants.htm

Hope this helps!

Not the best idea.

Just scatter your used coffee grounds outside in the garden in different areas each time.

u can just put the grounds on the plants..

Don't think it's a good idea. Only for acid loving outdoor plants :)

Mom always put grounds around her fuschias and camillias with great success! I put them in my composter. Leftover coffee, tea, soda pop, & alcoholic drinks diluted with water 1st are great for houseplants. I always fill beverage containers with water after guests leave and water things. No ant or bee problems in recycle bin later that way!