I recently added a garden hose splitter to my bib in my garage and outside, to be able to use 2 hoses at the same time from the same bib. I would sometimes need to run both my garage bib and outside bib at the same time, so there will potentially be 4 hoses running water simultaneously from 2 bibs. To give you a little context on my homes plumbing:
Main line coming into from the city is 3/4 inch copper. At some point, it changes to 3/4 inch PEX B, which feeds into the main lines of the home and hot water tank. All fixtures and hose bibs are 1/2 inch PEX.
Water pressure in my hoses was fine before adding the splitters, so I have a feeling the 1/2 inch PEX is not supplying enough water to keep pressure up in both hoses simultaneously. I would be able to run 3/4 inch PEX from the main lines to the hose bibs since they are located close to the 3/4 inch PEX main lines.
In your opinion, would increasing to 3/4 inch PEX help solve the low pressure issue? Would it be sufficient to run two hoses at full pressure simultaneously?