did you make sure the Perlite didnt have nutes? getting harder and harder to find untreated perlite.
enriched soil has its advantages... one of them being less need for mucking about with nutes... but the downside is there is no good way to control how the nutes are released... you wind up going from too much to not enough to right back to burnt quite often.
if you are wanting to use additional nutes you might just want to go to what is called a soilless mix. doing it this way means you have total control over the nutes. obviously, it is both more work and riskier.
the N-P-K is in the right direction with the Pennington stuff, so it should work.... of course, since you are using enriched soil, you will want to add this stuff with care and in small and slow doses and keep an eye on you pH.
the trick to any feeding is it is always easier to add some than it is to remove it.
just lost a plant this week due to not following that bit of advice