Best place for a water test

So I’ve been using my well water as my primary water source for a couple years now without issue. I knew it was hard water but it’s always had a consistent ph between 7.1-7.3.

Finally got a PPM pen as I plan to switch from hand watering to a DTW res so I no longer have to mix and hand feed every single day. It’ll give me a chance to take some days off and even vacation.
Anyway just to play around and see how the meter worked I just tested my tap/well water and it cane out to 420ppm. Now you’d figure with that number I’d never have to add cal mag but I run in coco under cob leds which both make things more calmag hungry but still 420ppm on a 500 scale would make you think I wouldn’t need any.

So now to figure out what is causing the large number I need to have it tested to see full mineral content. Anyone here know of any labs that do this kind of testing. Now I’ve never really had issues with the water so I know it’s not bad to use but I also know that large of a number will make reading a res fun.

I can get a free test from my county. I’m in the US. They send a small kit out and you send it back. They mail you the results. I should do that now that I’m in a new place.

Yeah the only test they do in my county is a toxin test.

There used to be a comp y that did a hydroponics water test that would give the npk ca mg of the water but I can’t find it anymore.
Honestly I’ve done fine with the water but would love to know the true ca to mg ratio of my source water