It
could work. My only concern is that it is limestone. Afterall, Portland Cement used in DIY rocks is crushed limestone and it starts out with a very high pH as well. I would advise against it and try to find a silica or aragonite sand.
Actually, any sand works really. Even silica based sands. The biggest difference is it doesn't look as natural.
Aragonite based sands, like southdown, aragamax, etc, only difference to silica based sand is that when the pH begins to drop below about 7.8 due to Carbonate (Alkalinity to most of us) and Calcium imbalance issues, the aragonite sand (Calcium Carbonate [CaCO3]) will dissolve and release Ca and CO3 back into your system to provide a small buffer until you can fix the problem. Aragonite sand is not a fix all solution and if your tank has been neglected to a level where this will happen, then it's time to start a new hobby
But, no all of that would be caused by neglect. Accidental overdosing would also cause this, but it would be quite extreme like spilling a bottle Calcium buffer in your tank. But, you should automatically see a difference in water clarity and immidiately be doing water changes anyways.
This benefit of having aragonite sand doesn't really come up often. Silica sands do not leak silicate back into the aquarium. This usually happens under extreme pressure, say, around 300 ft deep. Even then, people are starting to dose silicates into their aquariums.
Just some food for thought
One last thing. I'm in the process of hunting down a large quantity of aragonite sand, so I'll keep you posted if I find any. How much are you looking for?