These are geared towards shrimp
Which species? Who decided that GH:KH should be 1:.5?
A blended product is always suspicious to me.
How do THEY know what I need to add to MY water, and will it be the same if I change my water source? (perhaps they base their material on RO or DI water)
I prefer to buy each material separately, and add the amounts I want of each component, and I start with my tap water, which already has some carbonates, Ca and Mg.
When I find a material that is blended in a way that works for me, then, OK, I might use it, but only after pricing out the ingredients separately.
Many (by no means all) packages that contain KH raising materials use baking soda (Bicarbonate of soda, Sodium bicarbonate, similar names) which can be purchased a lot cheaper in the grocery store.