Correct, if your pH is 4.5, this is extremely acidic and not plant friendly at all!
Somewhere closer to 6.5 is where you should be aiming for.
Also remember, the more leaves you remove, the less energy your plant can make, thereby slowing growth and leading to (potentially) reduced yields too.
Try only ever removing yellow leaves, for once they are yellow, they have served their purpose.
Besides, if your plant did not need them, it would not have grown them in the first place!
Cheers, Organoman.