I took mine at 5momths but he dint like it at all :( i think the water was too cold cuase hes feet turned out purple but now hes 6 months n he loves it lol but I wouldn't recommend u takin him/her to small to the pool cuase of all the chlorine

whatever age you want. my son was swimming at 6 weeks old. he's 15 months now and never wants to leave the pool.