5.7 and 660 today. I topped up with nuted solution. They're drinking it up really well now

Weedhound, it's possible that your water is buffering PH already too. Here is a great article on water, and where I finally got the idea to try baking soda (never would have occured to me, as the common good advice is always stick with the professional ph adjusters): http://www.icmag.com/ic/showthread.php?t=23357

My plants are bursting with fresh growth now.