The "intermediate" rating comes from working with pressurized plumbing, requiring precise pipe cutting, and ensuring leak-free compression fittings. Beginners often find accurately measuring and cutting the main line, along with properly tightening fittings without over-tightening, to be the most challenging aspects.

Specialized tubing cutters are highly recommended for clean, straight cuts on copper pipe, which is crucial for a secure, leak-free connection with compression fittings. A hacksaw can leave burrs and uneven edges, significantly increasing the risk of leaks, making extra deburring and cleaning essential if used.

The most common mistakes include uneven pipe cuts, insufficient deburring, improper application of Teflon tape, and over-tightening or under-tightening compression fittings. To avoid leaks, ensure perfectly straight and burr-free pipe ends, apply Teflon tape clockwise on male threads, and tighten compression fittings just enough to seal, often with a final quarter to half turn past hand-tight.

A bypass loop allows you to isolate the filter system for cartridge changes or maintenance without shutting off your entire home's water supply. While technically you could install it without a bypass, it's strongly advised against, as it means you'd have no running water during filter service or if the filter housing needed repair.