Im having the same issues ..Im feeding at a PH of 7 ..my runoff is 5.5 to 5.7 ....When I make a sludge and test it ,it is 6.2 .If I let the sludge sit a few hours it drops to almost a perfect 6 .I let it sit overnight it was just a hair under 6 ...But I suspect that after I feed, the PH is...
Im using sunshine mix #4 with aggregate ...I mixed in more perlite for drainage ...Im having huge issues with PH ...I did not add lime because it says that there is lime already added .I am using Cal Mag instead ..I have alot of experience with indoor growing ,but have never used Sunshine mix...