I don't think the test is going to give you much useful info unless they are more demanding up north, but a sediment filter would be a big help and will most likely need to be replaced every month if it's a whole house filter.
We have well water and a whole house water conditioner that is basically DI resin that gets cleaned via a brine solution, they used to get a bad rap because of water with a high salt content but those issue are now minute. After it's conditioned the water is very soft with no gH but a kH of 5 or so and I have no idea what the TDS might be.
I also use a six stage RO/DI unit from Bulk Reef Supply, I have only had it in use for 2 months and I changed the sediment filter yesterday but my TDS are still zero going into the DI resin and the same when the water exits the DI. I do like having the super clean water and it has gotten to be routine using the holding tank and it is also much faster.
I change my water by turning a couple valves, pressing a button to start the pump, plus I get the front flower beds watered, and it all happens within 30 minutes on a 50 gallon water change.
This photo was taken after just 3 x 50 gallon tanks of water had been produced by the unit, you can see the sediment filter all the way on the left is already brownish in color.
Just a week earlier it was lily white, but the copper feed had sat un-used for years so there could have been some sediment in the line.