Flavoured water?

Hi, so I have brought this filter bottle to make flavoured water. What you do is but the fruit into the little compartment and fill it with water and the juice and stuff from the fruit turns the water flavoured. I was just wondering which fruit to use as I have heard lemon and lime juice is very acidic and is not great for crohns so does anyone have any suggestions on with fruit would suit my tummy best?

Banana is the only fruit I feel safe with

I find berries work well (black berries and raspberries and my top choice.

I can't do the skin or the seeds

I am sorry. My last statement would make no sense since you are talking about water