cfl and hps question??? someone please help...

ok so i know a little about indoor growing from reading on forums and also from growing outdoor, but this is my first indoor grow which is soil.. i have a cfl setup that consists of 4-23w cfl's, which are 6500k and 2-23w cfl's, which are 2700k and i have 3 plants under that setup.. and then i have a 150w hps setup in a separate closet that has 1 plant under it.. both setups and in the veg stage and on an 18/6 cycle. i feed both with a 20-20-20 at 1/4 strength and they both seem to be doing amazing.. i plan to switch both setups to a 12/12 cycle in a week or so.. so now this is where my questions come in... first, what kind of fertelizer should i switch to for flowering? and can i switch right over from the 20-20-20 or should i gradually introduce the new fertilizer? and second, would it be ok to put the hps and the cfl setup in the same closet when they are switched to the 12/12 cycle as long as they are both set to the same times? so pretty much it would be like having a cfl and a hps setup combined... or would i be better off leaving each setup in its own closet??

before you go 12/12 i would flush them. And you use flowering nutes, with i cant help you couse i dont do soil. 1st week in flower i use 1/2 strenght dose just so dont stunt them and them work my way up to full strenght ( highest is around 2.2 EC in full bloom). And your sencond question; yes again, more light more buddz just keep em on 12/12 and thats it

how long should i flush them before switching to 12/12? and also when switched to 12/12 i plan i switchin from 4-23w 6500k and 2-23w 2700k to the exact oposite for flowering.. so it would be 4-23w 2700k and 2-23w 6500k. would that be ok or should i leave them how they are right now?