heard the same thing .....ph 6.6 isnt bad though ...some people say 6.0 others 6.8 ....ph is ok ......I dont know about no 10-12 for seedlings but mine is at 46 and everything is fine so im thinking 123 maybe a little high ...and take what everyone says with a grain of salt ....what might work for one person might bomb for you ...never know ...