That would require a pretty major change to the database since we only currently support checkboxes, pulldowns or text fields.
Ideally we could put in the various ph ranges we want as checkboxes and you check off all that apply. If I add a slider later it would be easy for me to transition the data to slider form.
The only decision to make on pH is do we represent it as "Acidic" and "Basic" or do we get down into the nitty gritty of actual pH numbers.
