Hey Cripp 
The Soil PH meter (unless it was crazy expensive) won't really cut it for you.
What you really need is a PH pen.
Here's a link to my review of a cheap but decent pen https://www.autoflower.org/f156/essentials-ph-meter-28188.html - they're about £45
If you want something that is awesome and don't mind spending a few quid more - get the Bluelabs truncheon with PH and EC meter on. about £70ish
The Soil PH meter (unless it was crazy expensive) won't really cut it for you.
What you really need is a PH pen.
Here's a link to my review of a cheap but decent pen https://www.autoflower.org/f156/essentials-ph-meter-28188.html - they're about £45
If you want something that is awesome and don't mind spending a few quid more - get the Bluelabs truncheon with PH and EC meter on. about £70ish