I have only used the pool in winter, so cannot comment on the outdoor pools but the indoor pools are fantastic for some family swimming. There are a variety of pools and three different size slides. The roof is a huge glass dome, which makes it feel like you are outside - my kids had a fantastic time, as did...
Mirandabad is a really nice pool, there are a few different pools in the complex but the family area is great. Combining different depths with 3 slides and a wave machine makes for a great day, they also serve food.
It's always full of people use the outdoor pool during the summer. But you still can use te indoor pool. There are different programs for every ages, from baby till elderly people. The location is easy to find. From Amstel station, the bus number 65 will bring you to the Mirandabad. Price is affordable.