What should I bring for a day in Slide&Fun?

Swimming suit.
Towel and/or bathrobe – personal or can be rented on site (towel rental €4, bathrobe rental €8).
Slippers for the pool – personal or purchasable on site € 8.
Swim cap – personal or purchasable on site (€ 3 canvas cap, € 9 silicone cap).