I think there are other ...

I think there are other anti-scaling products. One reason to submit to your client is that  cooling water with Sulphuric acid as Ph rectification system will present two main handicaps:

1.- Rectify Ph water is not an antiscalant system. Calcium will be in the pipes/cooling system.

2.- Cooling water can have an evaporation degree. The acid addition should be done with cool water, and this evaporation rate will change the Acid rates and scaling issue will be there, a higher acid attack will be present due to Acid concentration is higher for evaporation and the anti-scaling goal will be not accomplished.