Trouble Getting Alk up in established tank dosing Nitrates

[gregzz4]

Just for clarity sake ...

I've been using Randy's recipe for years. When I wrote using a gallon of water for testing, I should have written 3785mls as I know this to mix perfectly.

And making your own SC, I place 594g of baking soda on a tinfoil-lined cookie sheet and bake it for 30 mins @ 300F.
This mixed into a total volume of 3785mls was perfect. Not adding it to 3785mls, but rather adding it to, say, 2-2.5l, then topping up to 3785mls.
If you add it to 3785mls you'll end up with a weak/diluted solution.