How we choose

What a product needs to be included

Tubing states its inside and outside diameter (or the maker prints it), not only a nominal size
Fittings state the tubing OD or ID they fit and their connection type (compression, barbed insert, spin-lock, hose thread or pipe thread)
Emitters and drip line state flow per emitter (GPH or L/h), whether they are pressure-compensating and the inlet type; drip line states emitter spacing
Head-assembly parts state thread type and gender on each end, maximum pressure and, for filters, mesh rating, and, for regulators, outlet pressure
Identifiable model or listing with stable specifications

What we exclude

Fertilizer injectors, fertigation, liquid fertilizers, pesticides, herbicides, chlorine or acid line cleaners and other chemicals
Claims that a backflow preventer or anti-siphon valve meets a local plumbing or health code, or that a system is safe to connect to drinking water (the site points to the local water authority and the maker's documentation)
Drinking-water, lead-free or food-safety claims for tubing and fittings beyond the maker's own stated certifications
Instructions for wiring controllers, valves, pumps or transformers to mains power, and work on household main water lines or meter connections
Water-saving, yield or plant-health guarantees, and water-use or flow figures beyond what the maker publishes or presented as tested by us
'Universal' or 'fits all' claims without the actual tubing diameters or thread types stated
Gas-powered or electric pumps, rainwater-tank systems and greywater systems (outside this segment)
Smart controllers, Wi-Fi hubs and in-ground sprinkler valves as recommendations (they appear only as the reference systems drip parts connect to)

Claims we do not make without specific evidence

No fertilizer injectors, fertigation, liquid fertilizers, pesticides, herbicides, chlorine or acid line cleaners and other chemicals
No claims that a backflow preventer or anti-siphon valve meets a local plumbing or health code, or that a system is safe to connect to drinking water (the site points to the local water authority and the maker's documentation)
No drinking-water, lead-free or food-safety claims for tubing and fittings beyond the maker's own stated certifications
No instructions for wiring controllers, valves, pumps or transformers to mains power, and work on household main water lines or meter connections
No water-saving, yield or plant-health guarantees, and water-use or flow figures beyond what the maker publishes or presented as tested by us
No 'Universal' or 'fits all' claims without the actual tubing diameters or thread types stated
No gas-powered or electric pumps, rainwater-tank systems and greywater systems (outside this segment)
No smart controllers, Wi-Fi hubs and in-ground sprinkler valves as recommendations (they appear only as the reference systems drip parts connect to)

Evidence labels

Tested by us: A named person used the exact product and variant and recorded the method, dates, results and limitations.
Research-based analysis: We compared published information from several sources without testing the product ourselves.
Manufacturer specification: The figure comes from the maker's documentation and has not been independently checked.
Seller claim: The figure comes from a marketplace listing and has not been independently checked.
Independent source finding: A named third party published the finding; we attribute it rather than repeat it as our own.

Prices

Articles do not contain prices. Where a price is shown, it is the merchant's quote for the shipping destination you chose, with the time it was checked; it disappears when it is no longer current. The price at checkout can differ.

Commissions and editorial choices

We may earn a commission from qualifying purchases. Commission rates do not decide which products we recommend, and any paid placement is labeled as such.

Dates

"Editorially reviewed" dates change only when someone re-checks the article. Price checks do not change them.