A very good (and inexpensive) PH up is food grade K2CO3 aka Potassium Carbonate or commonly known as potash or pearl ash. You can get a pound of it for around $10, and due to it’s high concentration will be enough to last you a very long time.
Potassium carbonate, K2CO3, is a standard ingredient in the wine industry. It may be also be used in pharmaceutical labs as a drying agent or to make soap, to make glass, and to soften water. Many growers also amend their soil with potash to help stabilize the ph.
Potassium carbonate is a very fine powder that instantly dissolves in water. You just need a few grains, literally a pinch of it, to significantly raise the ph.