Low pH & Carbonate Hardness

[chromakey]

Good Day:

I recently swapped out my live sand with 20 lbs of Caribsea Arag-Alive Fiji Pink sand from my 28 gallon JBJ tank yesterday and did a full set of water test today (10AM lights off). I use Reefer's Best salt and do not dose anything. I typically do a 4 gallon wc every two weeks or less. I have always had a problem of low pH and Hardness/alkalinty. It seems low but stable and was wondering if there is anything you would recommend. The only livestock that I have difficulty keeping is snails for some reason. I am not sure if this is related to ph/hardness.

Thanks,
Michael

SG: 1.024
Temp: 80 F
API Test Kits (not expired):
pH: 7.8
Amon: 0
Nitrate: 0
Nitrite: 0
Ca: 480
KH: 7 dKH
Phos: 0
Elos
Mg: 1200