Hi, welcome to HCM.
Firstly am glad you are open to symptoms and keep watching your child. However, as you mentioned, he is energetic enough which means he is fine. Also you can increase his iron levels by giving him jaggery, greens, raisins, lots of fruits etc. However, if he is drinking a lot of water, it might just be that he is thirsty. Is there child diabetes
history in your family? Else i think he is just thirsty may be due to climatic conditions/activity etc. However, if he shows signs of weight loss
, inactive, low energy, does not eat, then you might have to take him to a doc. Feed him foods that are rich in iron and calcium.
Good luck to you!!!