m0useanswered grow question 6 months ago Look up testing labs in your area, best option for cheep testing.
All good home testing kits will cost a ton as the tech in them is not cheep to produce but it is simple in how the results are posted normally some form of gas/light chromatography.
You can get the cheep ones that are a reactive dye you match up to a chart but that's not the best IMO and I'd just save money for a lab test.
Good Luck!