Hey Chas, ....are you suggesting I don't use it anymore? What about Ph Up and Down? I guess what I'm asking is....how do I get PH at the proper level if not using the Perfect PH. And....do you think I need to drain again or can it wait until it's time again? And in your opinion (which I value... :-) ), should I be putting 1 oz of Metal X weekly in the tub?
I don't recommend the pH balancing chems. Stick with pH up and pH down as needed and you'll be fine.
As for refilling the tub: I would. Water is the cheapest 'chem' you can add to the tub. If it's a real hassle to do this, then try this: turn off the power and open the drain or start a syphon. Let it just run out until the tub is about eight inches down from normal. Close the drain or stop the syphon. Refill. You will have just changed about half the volume of your spa and that might very well be enough. Also, it will heat back up quickly since your tub will be lukewarm when you are done. (Leave the cover closed while doing this)
As to metal stuff - I do think they are good insurance. I used to say "cheap insurance," but prices have crept up a bit...