Dude, you can literally get testers
for as little as 4 dollars these days.
You are going to get what you pay
for though. I always recommend
Blue Labs around $100, you don't
have to go that much, but you
should definitely get something.
Soil PH checkers are notoriously
bad unless you spend a lot of
money & even then the readings
are questionable at best
(somebody please correct me if
I'm wrong on this).
You would be much better off
to check your runoff water imo.
Growing cannabis indoors is not a
cost free endeavor if you want to
be as good as the pro's around
here.
The old adage: "you've got to
spend money to make money",
holds as true for growing as it
does for most of life's endeavors.
Do yourself (and everyone here
trying to help you) a favor and
get off some money & get some
decent meters so you're not just
guessing at shite.