10gal pots??? Really??? A little over kill don't ya think??? I can picture you moving them around with a dolly :jointsmile:....

Likely salts have built up at the bottom of the massive pots you're using which has caused the pH drop in the runoff....

If they're looking good and keep growing good....then it shouldn't be much to worry about.... Just keep an eye on them....one thing is for sure....they have enough soil space....

CGI::::::