You should be able to buy a pH buffer, that will raise your pH to like 8.0
I'm usually don't worry about pH so much, mine is usually around 7.5
I think most pet stores just keep them in average tap water, and I think they are used to a little lower pH.
It might not just be your pH, they're could be lots of things that cause them to scratch on rocks. High nitrates, chlorines, metals like iron in your water could cause this. You can buy a water conditioner, to remove harmful things and it helps the slim coat for your fish that will help them be healthier.
I'm usually don't worry about pH so much, mine is usually around 7.5
I think most pet stores just keep them in average tap water, and I think they are used to a little lower pH.
It might not just be your pH, they're could be lots of things that cause them to scratch on rocks. High nitrates, chlorines, metals like iron in your water could cause this. You can buy a water conditioner, to remove harmful things and it helps the slim coat for your fish that will help them be healthier.