first phalaenopsis ever - help

[1277cynthia]

hi, i got a mini-phalaenosis orchid from a friend. there wasn't a tag so i don't know its variety. its a light pink colour flower with dark pink veins. this is my every first orchid ever and i really want it to be healthy and rebloom. its been about a month since i got the plant and i see the leaves' edges are turning a bit yellow but its not that noticeable and the tip of the leaf is yellowing and splitting in half. the plant does not have any new growth and its flowers are falling. the roots are firm but wrinkled and kinda yellow&white or brown coloured and there isn't alot of roots on the plant. the leaves are firm but they are dull in colour and they feel bumpy like pores. there are little leaves at the bottom of the crown that are lose and falling off. the plant is in a 4" pot in bark medium and i water it once a week (on friday). its in a west facing window with bright light but not direct sunlight and its usually 16 - 21 celsius there. i feed the orchid the SCHULTZ brand 19-31-17 orchid food about one spoon once every 2 waterings. i'm doing something worng? and is my orchid healthy? how long will it take to grow a new leaf or root???