At what age did you let your babies get in pool? Baby pool bought from store

My 5 month old goes swimming with me all the time! He loves the water! He was 4 months when I first took him
We put our son in my grandmas pool when he was a few months old. He loves the water now & hes 1, so he tells you when he's cold which is after like 20-30 minutes.
Last year my baby was 5 months and I tried but he didn't like it and this summer he's 15 months and he loves it now. It just depends on you and baby, if you think it's warm enough.