Moderation is ALWAYS the best policy. Especially when dealing with plants, when you don't know if what you're doing to them is good or not.

Passis don't like "wet feet" so at first blush, watering every day is probably bad--unless you have them planted in very sandy soil that dries out that quickly. You'll have to evaluate your particular situation, taking into account soil type, size of the plants and size of the pots, but watering once every three days is more likely to be appropriate than every day.

As for fertilizer--what did the instructions say? I don't know of any plant food that you're supposed to apply every day. Passion flowers in general need less fertilizer than other flowering plants. And Miracid isn't even fertilizer, really. It is, as you said, a soil acidifier, for use in alkalai soils with low iron content. You may well have burned the roots beyond repair.

If you could tell us what kind of passion flowers you have, we might be able to give you more specific advice. But for right now, just step away. Don't do anything else. Let the soil dry out for several days, then begin a moderate watering program. No more attempts to fertilize the plants until they've recovered. If they can save themselves, they will. If not, there's nothing you can do that won't make the situation worse. Good luck.

Yes to everything Jblaschke posted. Water when they look like they need it and I feed my passies very infrequently, maybe every 6 weeks with an all purpose fertilizer and some kelp extract. I dig some chopped banana peels into the soil to provide extra potassium. It encourages flowers. Just a small spoonfull dug in well. More than that and you'll end up with fruit flies! You need to stop. You are killing them with kindness. Good luck, I hope they recover.
Karyn

thanks guys,
i'm now leaving them alone as you say. they are still flowering a little, which i'm hoping is a good sign. i'm not sure what type they are as i didn't buy them labelled. there are two layers of petals, one on top of the other. the middle ring is black, then white and the outer ring is purple. hope that helps.again, unfortunately i don't know about the soil - i repotted them when i bought them a year ago using compost we had in the garden - not sure what type it was.

thank you again for your time.