How much armor si?

Usually it will say on the bottle if it has to be used by a date or by open date. Like hydroguard is only good 6 months after opening. Could of went bad over time. I like to keep my bottles stored in a cool dark place. I use a cupboard to store bottles in so light isn't constantly beaming on my plant food or additives. Not sure what that could be from. Weird. I'd stop using it probably myself if I noticed something like that going on

And I always went without it before. Never any problems just wanted to see if it was beneficial at all so just recently picked up a bottle and it's still full pretty much cuz I stopped using it cuz if the high ph issue. General hydroponics recommends mixing armor si first then calimagic, then base nutrients, then additives, then ph. So I don't understand why people ph before adding other stuff. Just seems weird to me. Wasn't expensive so maybe I'll just call it a loss and not use it.