pH, TA, Bromine reading in new start spa

[kgriggs]

I just refilled my spa and started the testing procedure to balance the water. Fought with a high pH and low TA situation for a while. Is there a trick to get this situation under control? I just about have it after multiple dry acid and baking soda additions.

Then before adding anything I thought I would test the bromine/chlorine reading for fun. I had detectable levels prior to adding anything. I assume chlorine in the city water? THen I added a capful of MPS and now i have 2ppm detectedwith oto, 1 ppm detected with DPD, and 4ppm with the FAS-DPD test...

Is this typical? I still have ha hard time grasping the bromine residual and MPS balance issue.

Thanks!

 

[chem geek]

MPS measures as CC in the DPD test and as FC in the FAS-DPD test (not sure about OTO, but it seems to at least get partly measured there as well). You can get the Taylor K-2042 to remove interference from the MPS.

 

[JamesW]

Is this spa on chlorine or bromine? Have you added any sodium bromide?

 

[kgriggs]

The spa is bromine but this was on a fresh fill prior to any addition of bromine.