I have several spikes now and buds -yay! I have read about bloom booster ferts to be used once spikes appear, and encourage growth with extra nutrients.( mostly phosphorus?)

What are your experiences with using it? Most that are spike growing now bloomed last year, so I would have something to compare it to.
Do you think that it is worth using? And, are there any times that you can't use it, like right as buds open or anything?

Please share your experiences! Meg