tap water ph very low and hardness very high

[ehmia]

A GH of 0-30 or 60ppm is very soft water, 300ppm very hard. So buying the GH test kit to clarify is a good idea. You'll then be able to check and rectify any fluctuations.
Also sounds like a fine plan for the snail.

yeah just hoping the cory tank ph doesn’t end up going down to, im not sure whats causing the betta tank to be so low