you should do fibroscan and hbsag quantivite test.
The American AASLD guideline suggests no treatment if ALT is persistently normal and hbvdna is less than 20,000 iu/ml. But the APASL and EASL guides, both consider no treatment if ALT persistently normal and hbvdna is less than 2,000 iu/ml. So yours is a grey area, personally, I think it is best resolved by taking a Fibroscan - if there is no significant fibrosis, then you can wait and monitor, otherwise treat. With cirrhosis, any hbvdna level should be treated.
Just my opinion.