A couple months ago we received a letter from the company that put in
our water system with some specials they were running on their new,
more efficient systems.

I called them up and the guy said he come out and take a look at what
we had and decide if it would be worth our money to upgrade.

At first he looked at the system and said it's probably not worth the
upgrade. Then he did a TDS test on the water and it was over 600. He
said your tank is shot and needs to be replaced (or needed new resin
or whatever).

Considering the cost of replacement and the cost of the new system we
went with the new system ($3K).

After having the system for a while I decided to get a TDS tester and
test myself. Well, I get readings anywhere from 550-900 (never below
550). Our RO water shows around 20 so at least we know that is
working.

I measure around 550 on the water that doesn't go through the
softener.

Does it sound like the new softener is not doing it job? Are there
other reasons why the TDS might be high on the "softened" water?

The guy is coming back out tonight to test the water himself. I just
want to be prepared for any "excuses" he may have.

Thanks in advance