A few hours. Dropping ta will take the longest. Remember, only drop to 7.0 ph and aerate to increase ph. Each time it will drop ta a little. It may not make any change at first but then it will come down.
when you get your taylor kit read over it well.
What you will focus on is how to do the ph test and ta test. When you have your ph test you will perform an acid demand test on the ph results. This is basically just adding acid out of the taylor bottle until you get the desired ph color. You will do a drop, recap and invert to mix. Repeat until desired.
In the back of the taylor book is some charts, you will have to guesstimate your tub volume and might have to do some solve for x algebra to figure out dosing (I promise its not that complicated even if it sounds like it). Once you know your tub volume, ta, and ph with acid demand look on the chart for lowering ta. Find out how much muriatic acid(or dry acid) it will take to lower it that much. You will use this as a ballpark number when lowering ph. Then go to ph page and see how much acid to add to lower it the corresponding amount of drops. Subtract that amount of acid from your ta acid amount.
To summarize that I will use an example. Let’s say your have a ph of 7.8 and it takes 3 drops to lower to 7.0. You also have a TA of 250.
You will want to lower your TA to about 50 to keep ph in check, let’s say that takes 15 ounces of acid.
On your PH acid demand page it says to add 7 ounces to lower PH.
Take 15-7 and that leaves with 8 ounces left on lowering TA. As you lower ta it will take less acid each time to drop ph do it will start fast and end slow. When you get close to the amount needed (use judgement) for lowering ta go ahead and retest TA and see where you are and readjust your TA acid number. Redo the PH acid demand every time you are ready to adjust ph as it will change each time as TA is lowered.
You can look into doing borax in the tub to help keep your ph more steady also. Just note if you use borax you will have to add acid at the same tome to balance it (pool math will tell you how much). You could also get proteam gentle spa and that is ph neutral.
After that is all done dump in your required amount of sodium bromide for your tub and stir it around while the jets are running.
Then you are ready for chlorine to start sanitizing.
With all that budget about 2-3 hours to get it balanced but towards the end when ph starts taking longer to rise up you will have 10-15 minute breaks that you can do what ever then come back check ph readjust then back to the break.