when to top plants and do these look ok to switch to 12/12

hey all.
these are my girls well only 5 left due to males. there at 5 weeks from seed and am wondering what would have been a good time to top them at. am i too late?
there about 25cm should i be switching them to flower yet?
also need advice on how much to feed them as they look limp and bottom leaves are starting to die.
i dont know how often and how much (litres) to giv them. atm im feeding once a day bout 2 litres with a heap off runoff
i had them in smaller 175mm pots under flouros for first 2-3 weeks and they wer really healthy lush green and feeding a cup of nutes once a day. even the very first round leaves stayd healthy the whole time untill i transplanted into bigger pots and put under the hps i didnt know how much to feed anymore inthose pots and they started gettin sik.
im using coco with perlite mix. house and garden coco nutes. 5-6 ph 1.4 ec into pots.

i measured the runoff ec and it varies from 1.4 to 2 with each different pot so dunno.
any advice is appreciated.
cheers

First off, plants are looking pretty good. They are still young and look healthy, so i wouldn't go boosting the feedings anymore, especially if your runoff ec is between 1.4 and 2.0. you are in the 700-1000ppm range (.5 conversion), that's good for veg. As for flowering, you can flip them whenever you want. Personally, i wouldn't flip them yet. I would wait till they are at least a foot tall or they show sex and are matured. That will ensure you a decent yield and highest potency. For topping, most people wait until there are at least 5-6 notes before they top, but it depends on the grower (people do all kinds of different things, as a general rule though... 5-6 nodes before topping and don't top after the first week or two of flower. Preferrably top in veg or a week or two before you flip them to flower). You definately aren't too late to top them. If i were you (assuming your plants are at 6 nodes now), i would go ahead and top for 6-8 main colas (chop above the 3rd or 4th node), give them about 2 or 3 more weeks in veg, and then switch to flower. At that point, they will be about 8 weeks old (mature) and had some time to recover from the topping. Once you start flowering, you can slowly add a little more to your feeding (since you are watering everyday, i wouldn't go much over 2.0 ec.) and the plants will have a nice stretch so you will end up with 6-8 distinguished colas. Hope this helps and keep up the good work!

hey thanks for the reply!
the 5 i have left have shown sex and are female out of 14. the rest are male and had to get rid of.
theres one big one in there ide like to clone and ive taken few cuttins today to see how they go. second attempt at cloning after not so succesful first attemp.

theyre not as healthy as they look close up of lower leaves....
link >>>>>>> https://www.rollitup.org/marijuana-plant-problems/332261-bottom-leaves-turnin-yellow-rusty.html

alright, so based on those other pics, i would say that you are feeding them a little too often. Right now, im growing in 100% perlite hempy style and only water every other day. Since you are in coco (absorbs more than perlite), i would try to cut back a little. You should still be alright to top, but for the next week or so i would feed twice at 3/4 strength of your normal feeding and water once in between the two feedings with ph'd water of course. Damaged leaves typically won't fix themselves but if you look at some of the other healthy leaves, they will tell you what you need to know.