Bellariva was the first place, I visited. This is a great place if you have very small children with you, since there is a perfect pool area just for kids, which contains three pools with different water levels, so there is something for everyone, even a two year old as my daughter. What I didn't like so much was the fact that the kids' area was totally separated from the rest of the pool area and if you come here to get some sun you will only find it in the morning, since a lot of trees and the location of the kids' area create a complete shadow.
I didn't try the adults pool (50 meter), which was located at the other end of the area, but it looked great.
Like all the other pools, I went to, Bellariva has grass (or at least earth) around the pool area, and you can rent a sun bed for just around 3 euro. There is also a little bar inside, where you can get some sandwiches, salads and even pasta + of course coffee and ice cream.
Lungarno Aldo Moro 6. T. +39 055 6266007