"So, I changed the water in my hot tub about a month ago."
"I check the chemistry today"

That's the problem if you only did that. To not test the water in a month is no surprise that you have a scale build up and those early number would confirm that's exactly what you have if left alone for a month.

The new numbers are ok accept for the pH of 8. You do not want to use an abrasive on your spa but will most likely have to have it washed with an acid solution to remove the buildup. BEWARE, if you do this, all lines need blown out, WITH WATER IN THE SPA FIRST, to completely neutalize the acid in the lines. Monitor pH closely after start up to ensure you don't drop too low. Close the slide valves on your equipment prior to doing this work too.