Adding Bleach In Dichlor System (Skip Some Nitro Steps)

[apostlej2015]

If my water is balanced and CYA within 30-40PPM, is it ok to add bleach (the hottub would not be perfectly setup per Nitro's method like the borates part)? The pH and TA is perfect...TA based on CH and /poolcalculator/.

Or does nitro's method only work on fresh fills?

[dlleno]

I wouldn't switch to bleach with that low of a CYA especially if you have no borates on board.

The purpose of switching to bleach is to avoid the continued accumulation of CYA as you add dichlor repeatedly over time -- so the switch to bleach itself is not about the fresh fill, its about using the spa until you have achieved <some value> of CYA, and THEN switching to bleach. One memory device you can use to accomplish this is to measure out the total amount of dichlor that will introduce <your target CYA> into your spa. that will be some volume which you can measure. set that volume aside, and use it until it is all gone - that will be the signal to switch to bleach.

The purpose of borates is to provide pH buffering which will help avoid the pH rise that the switch to bleach would otherwise introduce. you can switch without borates on board, but watch out for the pH rise, and go back to dichlor if you need to. Consider delaying your switch to bleach for a longer period of time.

I have experimented with switching to bleach without borates present. you can do it, but it is difficult to manage pH:

1. I found that you have to flirt with a very low TA (mine was at 30ppm) which itself is a risk.

2. I had to delay the switch to bleach until later (didn't measure it but guessing 75-100ppm) in order to control pH rise