You mention that you increased potassium and phosphate. Are you using a "Bloom" commercial food. Generally they increase PO4 but stay moderate with K+ as this mineral is most valuable to make stems/leave strong.
I am too new to know too much about all this but have just switched over to a "bloom" formula which I plan to use until late winter.
Nick

I am currently using Better-Gro 11-35-15 and will continue until about Jan/Feb when I will switch over to 20-14-13. Both products have minor essential elements. Even though I am using the 1st product, I do give the higher N every 5th or 6th feeding and on occasion do a wash out.

I can't give any answers on why the buds blast or why there are empty sheaths but I do know that I've been told by some of the best growers in the business...orchids do not need Bloom Booster :nono:

Ive also been told this several times by a few different commercial growers here in Hawaii as well.

Ross-- what are your day/night temps like where this is growing? How much light would you estimate you are giving it? What media is it in & how often are you watering? What is the frequency of fertilizer application?

I concur with the others that "bloom boosters" are not needed for most orchids; a regular schedule of fertilizer application I believe is more the way to go. I'll post more catt x pics as they open...
Adam

Nice flower and the shading on this one is just beautiful. The only time I've had bud blast is when I changed the environment of the orchid. Once the sheath and/or buds are formed I don't change the position or location. I have a lot of cats. (maybe 65 or 70) and it's not a problem but does happen every now and then.

Day temps depend on outside temps, but in low 80s. Night temps down to 60s-70s.

It sits in south window next to the glass. I'd estimate 2500-3500 foot candles depending on intensity of sun.

It's in bark, sending down new roots, pseudobulbs look normal as do leaves. I water approx 2 times a week. Pot is a net pot and lots of air. I can check the medium and it looks good. I fertilize with 125ppm MSU mix/RO water every watering. Hope this helps.