We acquired a spa from a neighbor, cobbling together a few bits and pieces to make it work again. I'm slowly getting the hang of things in terms of chemicals but just wanted to check/ask a couple of things please.
Firstly my pH level tended to hover around 7.2 until I used pH Up. The alkalinity also went up, to nearly 180ppm, but is now down to 150 about 3 days later, but the pH is also down to around 7.2-7.3. I know 7.2 is at the low end of the scale but still okayish, but 180ppm is too high - but is that anything to worry about? Maybe if I can get pH to 7.3 and alkalinity to not exceed 150...?
Secondly, it says on the #2 spa chlorine I should shock the spa after every use (well, maybe more than just a quick dip). If I do this I can get the chlorine levels to 5ppm - but last time I did that it took a good 36 hours to come down to 3ppm, a safer swimming level. Obviously I don't want extended waiting periods like this! I wasn't sure if the cover should be on or off during this time, or if even if it would make a difference.
Thirdly, I have both Shock Plus and Oxidising Shock (different active ingredients). Both say to use after every spa use and once a week. Both list their features but I'm not sure which I should be using - for example, is one better for cloudy water while the other is better for foam/algae/whatever? I don't think I should use both, at least at the same time?
Finally, I know you shouldn't add more than one chemical at a time, and I think I read here that about an hour between doses should be ok. That's fine as I can adjust pH/alkalinity/chlorine at other times. But can I add #2 spa chlorine within minutes of #3 shock (reason being those would be added after use, while we're dripping wet and cold!).