Borates Questions

[NCFlyersFan]

To prevent hijacking Waterbear's Borate sticky, I'll start a new thread.

In that thread, JasonLion stated:

It is still possible to change the TA after adding borates, it is just significantly more difficult.

Why is that?

I finally got around to adding 20 Mule Team yesterday. Started with TA of 100. When I finished, TA was 130. It is only going to go up since my water supply is very high in TA which means I will eventually have to lower it. So, I just have to ask...HOW MUCH harder to lower TA??? Is it just a question of having to add more muriatic acid to achieve the desired pH reduction prior to aeration since pH is both carbonate and borate buffered?

On a slightly separate note, great calculator Jason. My pH was only off by about 0.2 units after I finished the borate addition procedure and that was my own fault (forgot to add the last 8 ounces of acid during the second borate addition). Had I rememberd to add that last cup, the calculator would have been dead on .

 

[JasonLion]

Perhaps "significantly more difficult" is not exactly the right phrase. There are a couple of additional challenges, if they add up to "significantly more difficult" is up to you.

First, lowering TA involves significant changes to the PH. Neither my Pool Calculator nor BleachCalc models the effects borates have on attempts to change the PH. Unless you feel comfortable with Chem Geek's PoolEquations (not easy for novices) or have an acid demand test, you will have to experiment more with the amount of acid needed to change the PH.

Second, all of the PH change steps take longer. Notably, you spend more time with the PH around 7.0, which isn't great for swimming. Without borates, the rise by aeration from 7.0 to 7.2 is quite quick. But with borates you spend more time with the PH low and may not want to swim at that time. Similarly, without borates the procedure is more forgiving of accidentally lowering the PH too far. Without borates the PH goes back up very quickly. With borates the PH might actually stay low long enough to be a risk to the liner or heat exchanger.

Finally, with borates the amounts of acid needed for large PH changes can be intimidating. Muriatic acid can cause damage if you use it incorrectly. It isn't really such a great idea to become used to using huge quantities of acid all at once. Try to maintain the correct level of care and respect for muriatic acid so you remain safe and don't damage the equipment. Even though you will be using large quantities, you still need to pay some attention to each quart.

 

[NCFlyersFan]

Thanks for the quick response, Jason. What it really sounds like this all adds up to is just a little more POP than usual when adjusting pH and TA. Not a problem. I love to flaot around and drink beer. It helps with my patience :-D !