Which ingredient in this Nutrient line causes pH to drop?

My tap water pH is ~ 7.5 pH.
When I add this Chempak 8 nutrient it drops pH to 6.4 pH.


Yet when I add Tomatorite nutrient to my ~ 7.5pH tap water the pH doesn't change and I have to use pH Down drops to lower it.
I'm just curious as to what causes this.

Tomatorite

Thanks

Phosphorus pentoxide

xtsho said:

Phosphorus pentoxide

Click to expand...

Thanks. So why does the Tomatorite which has the Phosphorus peroxide not effect the pH?
I take it its the quantity?

Moflow said:

Thanks. So why does the Tomatorite which has the Phosphorus peroxide not effect the pH?
I take it its the quantity?

Click to expand...

Yes I think so.