No. GH has nothing to do with pH.Gh is measurement of minerals in your water that keep your Ph more stable
It is the important measurement for fish, though.
Sites that say fish want a certain carbonate hardness (KH) are wrong.
Fish want certain levels of calcium and magnesium. GH.
Usually in nature the two (GH and KH) are similar, because they come from limestone or similar rock which supplies various amounts of calcium carbonates and magnesium carbonates. Not all waters are like this, but enough are that it is a reasonable way to set up an aquarium
You can do some research about the water hardness preferences and optimum temperature range for your fish.
are two good places to research fish.