Don't you add the Alk separately with ESV? Just mix up a batch with low alk (around 6-7).
I use IO so im not familiar with all the fancy new salt. I ventured out of my comfort zone with a box of Fritz and had a bad experience. Ive heard great things about ESV though. I used to get it from a local fish store premixed back in the day when i had a pico on my desk at work.
Yes, everything is added separate. I guess I could use even less of that one part to get an even lower starting alk for the change.
The ESV came on a reccomendation from a friend in the business. I really like it. No crummy slime in the brute can and quick mixing!