in other words a 1-4-2...
Do you have a lot of yellow leaves? Did you lose many fan leaves?
i'm using a 2-2-3 and it keeps most of the fan leaves green throughout flowering, which is needed for bud production.
I don't get the biggest of buds but I don't get airy buds either.
I have a 1-5-4 Bloom food which I find is best for last 2-4 weeks of flowering, cus when I switch to it the leaves immediately start to yellow. First 4 weeks just focus on maintaining green leaves and the buds will naturally pack on weight.
Alternatively you could use a more balanced bloom nute and add a small amount of pk booster. That's what I'm testing right now but I'm not sure if I see any difference.