Hi, My name is Tucker and I own a pet store here in Utah. We have 3 self-serve dog wash tubs that use a lot of water. The tub manufacturer made sure my contractor used 3/4" lines to the tubs. My contractor ended up using PEX and quite a few "T" and 90 degree fittings on the PEX. The black plastic fittings fit inside the PEX and no doubt restrict the diameter of the piping. When we have all three tubs going, our water flow/pressure is GREATLY reduced. I have considered replacing all of the black plastic fittings with sharkbite connections, since the sharkbite goes OVER the piping and may not reduce flow. Is this a good plan to remedy and free up some water flow?