What the fuck does that mean 0-0

If the pH of your soil is too acidic then you may want to bring
it back to a natural 7. What you need is Lime. Lime can be bought in
small containers from any grow shops. Just simply add some lime to
your soil the next time you water your plant. Only add small amounts
each time and then the next day use the pH meter to study the effects.
What you will find is that you will get to know your soil better than I
could describe here and know what it needs. Advanced growers know
how much lime they need to bump their acidic soil back to 7. They
know this by trial and error. This is one thing about cannabis growing.
The best cannabis growers grow good cannabis because they have
made many mistakes in the past.