Sounds like something was in the lines.
pH and Alk are important. Here are a few snippets I've copied/pasted from previous answers I've given:
"pH lowering trick:
Add whatever you are using to lower the pH (Muriatic Acid, Sodium Bisulfate) and DO NOT RUN THE JETS. Let the water stay calm. This will encourage the reducing agent to work more effectively. I do this all the time in our in ground pools and hot tubs here in the store. In fact, I know that it takes 4oz of sodium bisulfate to lower the pH from the tap when I am filling a new tub on the showroom floor. Thus- I toss the 4oz of dry powder into the footwell and by the time the tub is filled the pH is pretty spot-on.
Try this and I bet you'll be fine. The only way it doesn't work is if you're testing your pH at, say, 8.6 and that is the highest your pH reader can read but in actuality your pH is, say, 11. That is why you're adding so much reducer."
....and....
"Make it easy and look at it in general terms:
Most sanitizers need pH levels to be set anywhere from 7.2-7.8. It just depends on the SPECIFIC sanitizer you use.
If pH is 7.9 or higher, it needs to be lowered. If it is 7.2 or lower, it needs to be raised.
Additionally, you should have your alkalinity level set usually between 80 to 120 ppm (parts per million). But in some cases its 100-150ppm, again, depending on the sanitizer.
Alkalinity keeps the pH from fluctuating and acts as a buffer between the things that want to make the pH increase or decrease and the pH itself.
Muriatic acid REDUCES pH and alkalinity.
The quality of your pH level = the quality of your sanitizer. Example: If your sanitizer (Lets say chlorine) was reading 3ppm but your pH was, say, 6.8, the quality of your sanitizer would be low. If I was to guess I'd say that the 3ppm reading was really only 1.5ppm active. I don't know the math but you get the point, and I am sure someone can correct my math on here.
Additionally: Keeping pH in line helps with the quality and life of your jets and heater and other components. High pH over time degrades metals, causing pitting, etc. and low pH over time causes metal deposits. This is not covered under warranty."
....So....
Keep your pH and alk in line and things work better. Keep your sanitizer level good too, based on whatever you're using...