They need lots of light to produce blooms. At least that is my experience. I had them in an area last year that would get maybe five hours winter sun and I had few blooms. Almost no blooms until close to spring when the sun light was stronger. This year I have them in a location that gets sun from early morning until late afternoon and they are blooming beautifully. I use water soluable fertilizer (the blue stuff). I think they can absorb the nutrients a little faster than the granular time release type.

Stop using that fertilizer and switch to one with a different analysis. You should be able to find something along the lines of 10-30-10, which is more appropriate for flowering and fruiting plants.

Just use Miracle Grow every 2-3 weeks for those in pots and once every 4-6 weeks for those in the ground. 1 tablespoon per gallon. I have tons of pansies and as long as they get adequate light, and regular Miracle Grow, they bloom non stop.
I prefer to use a bucket and hose rather than a hose end feeder which I don't trust. I also use a pansy fertilizer in the planting hole when I plant but you still need a Miracle Grow type fertilizer throughout the season.