Aeration - When To Use It When Balancing Ph And Ta?

[michy]

Hi,

My pH is stuck at 7.8 and my TA is 90. I've read Nitro's guide to lowering TA without affecting pH but it confuses me. I know I need to focus on getting my TA lower with dry acid. Say around 60, to get my pH right and stable. What I am not sure of is do I add the acid and aerate (turn on jets and blower)? Acid + aeration = lower TA. acid only = lower pH. - according to what I've read on these forums. I've been using the pool calculator and adding little bits of acid at a time, but am not sure i am using aeration at the right times.

When do I aerate and when do I not? I know the water will be balanced when aeration doesn't raise my pH. But when do I aerate when adding acid in an effort to lower TA and/or pH?

Thanks,

Michy

[PaulR]

When do I aerate and when do I not?

Nitro's procedure has you aerate the whole time. So I guess I am confused about your confusion. You add acid which lowers pH and TA, then aeration raises pH without affecting anything else. Simplistically, you aerate when pH is low, and don't when it's where you want (or too high).

I know the water will be balanced when aeration doesn't raise my pH.

That sounds wrong, actually. Balanced water will (in a typical spa) still see a pH rise when you have the bubbles on, just not as much of a rise as when your TA is too high. You do want some TA because it actually has some pH buffering effect.

--paulr

[michy]

I'm probably just confusing myself but Nitro's guide is for lowering TA without lowering pH. I need to lower both. ... that coupled with the fact that from what i've read, aeration raises pH but aeration also lowers TA. So what do you do when you're trying to lower pH and TA? That's where I am confused. So you're saying if I want to lower both my TA and pH then add acid and aerate?

Thanks!

Michy

[quantumchromodynamics]

Lower your pH to 7.1 and then aerate to raise the pH back to 7.8 to 7.9. Do this a few times until your alkalinity is where you want it. On the last cycle, aerate to raise your pH only to the desired level.

[Vince22]

Lower your pH to 7.1 and then aerate to raise the pH back to 7.8 to 7.9. Do this a few times until your alkalinity is where you want it. On the last cycle, aerate to raise your pH only to the desired level.

Should the TA and PH at rest (no aeration) be set to optimal levels? Or should one aim to get optimal PH level only once the aeration is on. I mean this as an ongoing thing. The reason I ask is that it's all fine and dandy to set the TA and PH at rest so that PH is optimal only when the jets are going (I presume for bather skin comfort), but what about the other 23 hours per day when the jets aren't on?

Since the saturation index affects the components of the tub, wouldn't those 23 hours be the most important (to protect the tub) and just have a non-optimum (high) PH when bathing with the jets on?

[Nitro]

My pH rises to ~7.8 after I use the tub, and drops to ~7.6 before the next soak.

To answer the question. Lower TA until pH stays at or below 8.0 when the jets are on.

[michy]

Ok, Nitro, that makes sense. I just tested the water after running the jets and blower for 5 minutes and now have pH 8.0 and TA of 50. Compared to last night, where I got it down to a pH of 7.6 and a TA of 50. Maybe I should wait until tomorrow and do a test before dip (no aeration) and after dip (with aeration)?

[chem geek]

If your pH tends to rise too much even at a TA of 50 ppm, then you should consider using 50 ppm Borates for additional pH buffering.

[carlee33]

99% of spa owners will have no difficulty getting their water into proper balance. But like hot tub users themselves, there's great diversity in water types from region to region, even within communities. a plus certification Municipal water supplies differ from well water. This sometimes leads to difficulty in getting pH and Total Alkalinity (TA) into balance.

[Paulette Goodson]

my ph is too high and the ph decreaser says to turn the aerator off when you put it in. I just got my jacuzzi and I am in the learning phase still. I don’t know if I have an aerator. I don’t see anything in the instruction manual. Can you help me

Paulette