Blueberry fertilising

I've got three pots of blueberries planted earlier this year.  In ericaceous compost (with John Innes).  I think at the time I threw in some fish blood & bone.

They are all flowering now, should I be fertilising with tomato fertiliser / ericaceous fertiliser / nothing at all?

Bit confused as information online seems to be contradictory - some say only fertilise once, each spring, others ericaceous fertiliser every 2 months, or monthly.  Others say high potash (e.g. tomato feed) every couple of weeks.

Whats the general advice please?