Fertilizer Question and Flower Stalks

[Cymbaline]

I have an Oncidium which is growing a flower stalk and I've been giving it MSU fertilizer which says it's 13-3-15.

Should I switch to something with more than 3 in the NPK ratio or is it too late now that it has a stalk already?

[SouthPark]

cymbaline - your fertiliser is just fine I reckon. Mine is 10:3:14.

I just fertilise once a month (weak fertiliser). That's what I've always done.

[Cymbaline]

Thank you