Okay to use PhDown instead of muriatic acid while adding borax?

I am using the protocol to raise my borates that is found on this site. I don't have muriatic acid but I do have a 25 lb tub of PhDown (sodium bisulfate) that the pool guys left when they installed my pool. Is that a reasonable alternative to lower the Ph during this process? I have a vinyl pool, CYA is 60, FC maintained at 5-7, TA is 90, Ph is 7.5 after adding some borax, city water in our pool. forgot my CH reading but I know it's not overly high.