What to do if I have like a crakling in my ear and What to do if I have just went to a pool earlier this day, what is it?

Eustachian tube. Hello, your ear symptoms sound like they are due to a eustachian tube dysfunction. The lining in your nose continues into the eustachian tube. Any condition affecting your nose will in turn cause ear symptoms. I would recommend afrin nasal spray as directed for 5 days. An otc decongestant can be used as directed thereafter for 7-10 days. If the symptoms persist, then see your ent.