can nute burn get WORSE after 24 hours of flushing?

Hey guys. Just finished day 8 in the dwc system. I think I overfed them the first week and now Ive been flushing for 24 hours now and was planning on flushing them another 24-48 hours. They seem to be getting a little better but the burned tips (and a very small burn on top) arent repairing themselves. they still look a little burned. Is this normal? Also you can see the leaves on one plant twisted. Did my leaves twist like this because I overfed them or is it something else? pH problem? Also, the burns actually seemed to get a little worse EVEN after getting flushed 24 hours. Does that mean its a pH problem and not a nute burn after all? I mean it didnt get much worse, someone else may have not even noticed any change but I think it was there. Is that possible with nute burn? Heres the pics, hard to see in the pics, they are blurry. Thanks for your help everyone, dont know what I'd do without you guys, theres so much to learn by head is exploding!

btw: I have no idea what that white chalk/salt like shit is on the lid. It just showed up one day, I think it happened while I moved the lid to dump the rez. I gotta wipe that shit off. Also, if it matters, they arent clones I started them from seeds 3 weeks ago approx.

i just checked em again and the burn is definately more pronounced. How can this be? Theres no nutes in the rez at all... Just ph down and a little ph up but just a few drops and thats its. Its distilled water. My ph is always 5.5-6.1 (It seems to be climbing rapidly and I adjust it about 3 times a day. It climbs .5 every couple hours. Is that normal?

wish i could help, looks like your in trouble. happy growing.

the necrotic spots wont come back. it takes from what ive seen in my aero system about three days to show what happen threedays ago. id say flush for a couple more days, but you may have stunted those plants and they MIGHT not grow to there full potential.. if you just started your grow and can easily reinsert clones you might want to consider it. one of my plants were stunted by too much nutes i can tell cause all my others are about 1.5 feet taller. going to get about half the yeild than the rest.

If your having a hard time controlling your ph it could more than likely be that the nute is too strong, when i have a concentrated amount (as my water evaporates or is used by the plants) the ph rises.. i can be hard to control so yes its normal BUT i think your over feeding your plants. LESS IS MORE to start anyways.

*sigh*.. this doesnt sounds good..

seriously, thats it? they're done? all hope is lost?

wow, that sucks... guess I'm starting over...