Hi Mana,
Thank you for your review of the Delta Faucet model 75554C. Please accept our sincere apology for the inconvenience you are experiencing. We are happy to help.
If the flow from the showerhead is less than the expected 1.75 gpm, we recommend flushing the shower faucet with the showerhead removed and cleaning any water debris that may be trapped in the connection.
As the manufacturer, we are committed to supplying you with a quality product that delivers the expected performance. Please reach out with any questions!
Best Regards,
Bryan
Digital Communications Specialist
(800) 345-3358
customerservice@deltafaucet.com