ELI5 Toilets - why are public toilets tankless unlike those at home?

Why do home toilets typically have tanks, while public toilets often don't? What are some benefits of tankless toilets in public spaces from a design perspective? What is the S bend there for and how has this toilet design influenced modern plumbing? What are the implications of Hong Kong using seawater for toilet flushing in a densely populated city? What toilet innovations do you find most significant in improving sanitation and quality of life globally? ... we explain like I'm five Thank you to the r/explainlikeimfive community and in particular the following users whose questions and comments formed the basis of this discussion: metrumax, rinsetorepeat, wouldbewanderer, toosmalley, jlowu571, j4ckr4bb1tsl1ms, dysgraphical, and guywithasockpuppet. To the community that has supported us so far, thanks for all your feedback and comments. Join us on Twitter: https://www.twitter.com/eli5ThePodcast/ or send us an e-mail: [email protected]