Well with 12 day old seedlings...exactly how much is "half strength nutes?" At that age they really don't need ANY nutes so perhaps you are burning them (overnuting) and that's what's causing the high ph. Just a guess on my part but I like it....

Try straight ph'd water on them and see if it helps correct the issue.

good luck.
Weedhound Reviewed by Weedhound on . PH Maddness!!! mornin to all members luv the site and very impressed with all the years of experience on the forum. this is my first grow and first post. I decided to WASTE money and use around-the-way seeds just to learn what I'm doing. my e&b system holds 10 seedlings in there 12th day. with 4 4' cool fluorescent light and half strength nuts. my problem is with ph levels. using mineral water i still had to adjust the ph with vinegar and Iā??m watering twice a day. since this is my first grow Iā??m very Rating: 5