There are many articles online about the benefits of having aquariums in waiting rooms to reduce stress. Below are the the research studies that these articles are based on and back up these findings.
The effects of interacting with fish in aquariums on human health and well-being: A systematic review – National Center for Biotechnology Information
Animal Assisted Therapy and Nutrition in Alzheimer’s Disease – National Center for Biotechnology Information
Here are a few articles:
Fish tanks lower blood pressure and heart rate – The Telegraph
Can Fish And Plants Help Employees Stay More Relaxed? – Healthnetpulse.com
Aquarium Deliver Health and Well Being Benefits – Eurekalert.org
Study: Aquariums may pacify Alzheimer’s patients – Purdue News