Drain and Fill feeding

I have a drain and fill set-up with a 8 gallon res. I have been feeding them 9 times a day but started to get leaf damage so i cut it back to 7 times a day. I was curious how often should the pump turn on to feed and should i only do it during the time the light is on? They are flowering now so I have them on 12 hrs. I have tried numerous things, dropped nutri strength, added espon, raised light. Nothing seems to be working so im curious if im watering/feeding too much?

3 or 4 times with lights on is all you need.

do you think that is what is causes my babies leafs to look like shit? All tips brown and curling, brown spots? Over nutri since they are getting watered/fed 3 times with lights and 3 without?

Nute burn and not enough O2.

Well your flooding way to much.
as for the nute burn what ppm is your nutes at?