Phalaenopsis with ragged looking blooms

[Setebos]

Hello everyone :

I have 6 phalaenopsis and I'm currently experiencing a strange problem with 4 of them. They have really weird looking flowers and I'm worried it may be to do with my feeding?

I'm afraid I don't know any species, all my orchids have been supermarket-bought gifts, or refugees!

Onto the problem and pics. Recent blooms look ragged, as if someone's shredded the edges or something! I have photos from 3 of my plants, here they are:








(Sorry if pics are too big)

At the moment I am watering my orchids every week and have been giving them this "bloom feed" 3 weeks in a row and then one week of just water. I will start watering more as we come up to summer, but I want to check first that this problem is not to do with my feeding regime!

Thanks loads for any insight!