Which is the best floating market in Bangkok?

While "best" is subjective, the most popular ones are the Khlong Lat Mayom floating market, Amphawa floating market Bangkok and the Damnoen Saduak Floating Market.

Are floating markets safe for children of all ages?

Yes, they are absolutely safe. However, pushing a pram through the narrow alleyways and hopping onto a long tail boat might be a bit of a hassle. Also keep a close watch on toddlers as these markets can get extremely crowded.

Are floating markets in Bangkok open during the weekdays? Why do they close early?

Most of the Bangkok floating markets are open on weekdays, however a few of them are set up only on weekends. Most of them close early as they sell fresh produce which grows stale over the course of the day.