Bio bizz making soil acidic

What’s up guys!
I recently switched from coco and salts back to bio bizz in soil. I have been having some issues with the root zone. My Feed going in is 6.5ph but coming out is 5.2-5.9 I am getting burnt tips, twisted growth and nutrient deficiencies!
Any idea what could be causing this?
This is what I’m using exactly, it was given to my by a buddy who has excellent success with it
power si and mammoth P @.5ml/gal
7.6ml/gal of grow, heaven
1tsp/gal oily cann

Hi buddie , did you find an answer to your issue after?? Somthing very similar happened to me and I think in the end I found out that it was that the peat was all used up in my soil and my soil ph level then started drifting ,which then needed dolomite lime to rectify the issue . I ended up having to buy a decent soil ph metre by bluelab to keep a future close eye on soil ph .