Will I fight pH forever?

[mphare]

I have an Aquarite salt system. I gather this contributes to a constant rise in pH.

I also aerate constantly as I have a 2~3 foot drop waterfall and a bubbler/fountain on a tanning ledge. If the pool is running, so are the water affects. This also contributes to a rise in pH.

So, my question is, will I be fighting pH forever?

Also, what bearing will this have on my TA since my pH never drops very low, I never get to convert to CO2 to be aerated out the water affects.

[KurtV]

Yes, you'll always have to add acid to lower pH with an SWG (or SWC); at least that seems always to be the case.

As far as alkalinity and aeration, why are you worried about it? Do you need to lower your alkalinity? If not and if your pH stays at or above 7.2 or so, the aeration shouldn't affect TA much at all.

[Davenj]

Check the Dealing with Alkalinity forum. Constanlty aerating lowers TA. SWG raises ph over time. I don't have a gunite pool, so I can't answer what effects or your levels need to be. You might want to list your water test readings. The people that can really help you will want this info.

[KurtV]

Check the Dealing with Alkalinity forum. Constanlty aerating lowers TA.

As I understand the process, your alkalinity won't be lowered by the aeration unless you lower pH to under 7.2 or so.

Dave is right, posting all your test results will get you better advice.

[mphare]

I'm trying to correlate all I've learned/read on this forum.

What I think I know:

Aeration only raises pH, not lower TA. The idea is to lower pH low enough to also lower TA, then raise pH through aeration, which doesn't raise TA, the net effect is TA is lower whil pH remains the same.

However, in order for this work work, pH must be low enough for the TA to be converted to CO2, which means pH of 6.8 or so.

As I said, this is what I think I know.

My TA tends to creep rather high, has ever since the pool started up 3 seasons ago. It was as high as 150 a few weeks ago. It's now down to about 100.

Since my pH never goes below 7.5, I don't think I ever get much of the reduced TA benefit.

At least, that's what I think I know.

[mphare]

I'll post number this weekend after I test them again.
I've posted them elsewhere in other threads.

This was really just a general question about constant aeration.

Thanks for the help!

[CarlD]

If your pH is over 7.2, aeration should not have an effect.

TECHNICALLY, aeration does lower TA, but practically it doesn't.

TA rises and falls with pH, generally, but when we aerate it doesn't. pH rises, but TA stays the same.

My understanding is that the amount it actually lowers TA is offset by TA rising with the rise in pH. The net effect is zero change in TA.

So while the chemists will tell you that aeration actually lowers TA, when we use it to raise pH, we don't see TA change and therefore say it's the only way to raise pH (after we lower it to lower TA) without raising TA again.

Since this process only works when pH is at 7.2 or lower, it shouldn't affect your pool. Try keeping TA higher--say 125-130 at a normal pH--and see if your pH rises as fast.

[PoolDoc]

I have an Aquarite salt system. I gather this contributes to a constant rise in pH.

I also aerate constantly as I have a 2~3 foot drop waterfall and a bubbler/fountain on a tanning ledge. If the pool is running, so are the water affects. This also contributes to a rise in pH.

So, my question is, will I be fighting pH forever?

Also, what bearing will this have on my TA since my pH never drops very low, I never get to convert to CO2 to be aerated out the water affects.

"mphare", from the way you put your questions, I get the impression that maybe you are doing your 'worrying in advance'? If so, I'd encourage you NOT to do so. Pools, including pools with SWG's all run differently. You need to run your pool, assess what's happening, and then correct what's going wrong on YOUR pool.

• Some, but NOT all, pools with SWGs experience a constant low-level acid demand. Until you've operated your pool for a while, you don't know that your is one of these.
• ALL waterfalls consume ALK, if you maintain an appropriate pH level. Levels above 7.2 aren't very good for *deliberately* lowering ALK, but if you have a continuously running waterfall, AND maintain a pH below 7.8, you WILL experience a permanent and continuous demand for both ALK and acid . . . completely apart from your SWG. The demand *may* be very small, depending on other factors. Waterfalls and fountains are pretty, but always complicate pool care. How much, depends on YOUR pool. (Maintaining a pH around 8.2 will stop the drift, but isn't practical, unless you have a vinyl or FG pool, and no heater. Even then, it isn't very practical.)

Ben
"PoolDoc"