Good question man. I didn't think of this when I didn't first grow and I have since changed to a different brand after learning a couple things. I can't tell you exactly what the ingredients are, but it's a very, simple acid base solution. And there isn't much of any difference between pH downs besides concentrations.
I first bought General Hydroponics pH down with 237ml worth for 8-9 bucks. We go through a lot of this stuff (well me, anyway. Very high pH water table where I live) and that's expensive... So I tried a brand called future harvest. One liter, exactly twice the concentration, exact same results...9 bucks😮. I realized I was buying brand name and besides organic pH down solutions, there's really any, if nothing, of a difference between them. Get bang for your buck with pH up and down. Nutrients are where the cash is more important.
Cheers man👍👍 Happy grows
