
Good call mate, on the epsoms and Maxibloom... there's more than one thing in play here, including some normal fading of lower fans,... but the color fade overall, particularly at the mid-level to tops (worst), usually that's a sign of S defc.; on the top leaves, are there any spots? I can't quite tell, but it looks like there's some purple-red color starting too (petioles as well?), could be early P defc.... at this stage demand for P, K Ca, Mg is elevated,...often see micronutrient defc.'s kick in too,... So, you've covered the S and Mg with the epsoms-- that's 1tsp/gal? The Maxi' should cover the other stuff,.... As for pH, 6.4 is good, but technically, without knowing what it was going in, it's not a valid reading; a calculation needs to be made to be sure... I dislike the run-off method for it's many potential sources of measurement error, but here's sticky article on a procedure that helps eliminate some of this ->
https://www.autoflower.org/threads/...-for-run-off-testing-and-ph-estimation.41733/
....ultimately, the best way to measure soil pH is directly in-soil, with a probe; Accurate 8 makes a good one for the money! ...Well, it'll take a few days for things to get in there and working, so meantime, watch to see if the symtpoms stop progressing,... likely, most of it won't reverse, it's halting that's important,...
