Re: Does BBB really make since when bleach raises PH so much
As I noted in
this post in response to your other thread, it is your hybrid approach where you are using Trichlor and therefore needing a higher TA that makes it more difficult to then later use bleach because the higher TA causes more carbon dioxide outgassing which makes the pH rise. As Jason noted, aeration can accelerate such outgassing and he also noted the curing of plaster which is like adding calcium hydroxide as a base to the pool that makes the pH rise and requires Muriatic Acid to lower it.
BBB does not mean you literally regularly use bleach, borax and baking soda. In fact, one only regularly needs to use bleach (or chlorinating liquid) and on occasion some acid (assuming you keep your TA level lower). If you use Borax, then that's usually a one-time dose (along with Muriatic Acid) to get to 50 ppm Borates, though by itself it can be used to raise pH but as you point out that is not normally needed when using bleach. You wouldn't normally need to use baking soda. The origin of the term BBB came from examples of grocery store equivalent chemicals to what is offered in pool stores as chlorinating liquid (or other forms of chlorine),
ProTeam® Supreme, and Alkalinity Up. While you are using Trichlor, the TA will drop slowly over time so you could use baking soda to raise the TA and you could use Borax to raise the pH.
Perhaps this table may be helpful for you to figure things out for what happens over time:
Product/Process ......
pH ....
TA ....
CH ....
CYA
Higher TA .................. + ...... 0 ....... 0 ....... 0
More Aeration ............ + ...... 0 ....... 0 ....... 0
Plaster Curing ............ ++ ... ++ .... + ....... 0
Trichlor Pucks/Tabs ... -- ..... -- ...... 0 ....... +
Dichlor ....................... - ....... - ........ 0 ...... ++
Cal-Hypo .................... 0 ....... 0 ....... + ....... 0
Bleach ......................... 0 ....... 0 ....... 0 ........ 0
Chlorinating Liquid ..... 0 ....... 0 ....... 0 ........ 0
The above shows the net effects assuming that any added chlorine is consumed/used either by breakdown from sunlight or from oxidizing ammonia or organics, both of which are acidic processes so net pH of hypochlorite sources of chlorine is roughly pH neutral (slightly increasing pH from excess lye).
This recent thread shows how a much lower TA led to pH stability, but in that case it is lower than would be recommended or needed to protect plaster (that particular pool is fiberglass).