Difficulty balancing pH and TA in new hot tub

[mxnonbinary]

For the past 3 days I have been trying to balance the pH and TA in my new Intex PureSpa.  I have the impression that these need to be balanced before adding any other chemicals.  I have done 24 tests in 3 days, and have made 23 adjustments, using only pH Down and Alkalinity Increaser.  I am using up a lot of test solutions (in the Taylor test kit) and a lot of chemicals.  I have added the pH Down and the Alkalinity Increaser separately, always running the cartridge filter pump and the jets.  The jets shut off after 30 minutes, and at some point after that, I retest.  I am pretty sure that I need to run the filtration pump after adding chemicals, but should I be running the jets afterward?  Or should I be waiting longer to retest?  I was trying to reach a pH of 7.6 and a TA of 60.  The hot tub manual allows for a TA of 60 - 120 and a pH of 7.2 - 7.8.  My untreated water had a pH of 7.8 and a TA of 120 - 130.   During my adjustments, I have had TAs ranging from 0 to 80, and pHs ranging from a yellow color to over 8.0, but they are most often 7.8 - 8.0 or higher.  Each adjustment of either of these throws the other one off.  I am going away in 2 days for a period of 8 days.  I may not have the chemistry balanced before I leave, and so I don't expect to be able to try out the hot tub until after I get back.  I had planned to shock the hot tub before leaving.  No sanitizer has been added, as of yet.  I plan to use Dichlor.  My last test showed a TA of 70 and a pH of 7.9.  Any advice?

 

[mxnonbinary]

After adding a tiny bit of pH Down last night and running the filtration pump, but not the jets, all night, this morning I was able to get it to what I considered "good enough for now," with a TA of 60 and pH of 7.8.  I added dichlor, eventually getting an FC of 5.8 and a CC of 0.  The CYA was negligible at this point.  The CH was 150.  I added a little more CYA in a sock.   Later, I tried it out for the first time.   I plan to keep the temperature like that of a warm pool, rather than hot, and today the water was 88 degrees F.   I enjoyed being in the tub and will keep on working to get my numbers more in line.