Mills nutrients pH spread in and out

[Curly Beaver]

I have a 4 week old Durga Mata ll CBD in FFOC/Perlite/PromixBX using the Mills Nutrients line up. My pH was 6-6.5 going in but the runoff is 4-4.5. That seems like a large spread to me...
Is it OK, and if not, what should I do...flush? SledgeHammer? Just leave it alone?
The plant looks great so I don't want to create a problem if none exists.
Thanks.

 

[Major PITA]

If it ain't broke, don't fix it.
My Promix is not that acid, and of course the perlite isn't either. I have no experience with FF. I expect a drop, but that does seem like a lot. I'd continue to monitor it but leave well enough alone for the time being.

 

[Curly Beaver]

If it wasn't so healthy looking I would be concerned. Somethin just doesn't sound right though.

 

[Major PITA]

When I was getting PH drops like that, there was a problem, but it was very obvious. I also was not in soil at that time (rockwool). The PH swings did a number on them. Yours looks great!