Lowering TA. How patient do I need to be?

[AftonJeeper]

So even before I received my TF-100 on Monday I have been trying to lower my TA with aeration and acid. I can't get my pH over 7.2, about 4 hours of aeration per day. pH went from 7.2 on Monday (added 1 gallon of home depot muriatic acid) to 6.8 Tuesday to 7.0 on Wednesday.

I built a bubbler out of some PEX piping and some couplings I had and hooked it up to an air compressor. Zip tied a weight to it and toss it in the deep end. Also have a small water fall that I turn on when I run the bubbler.



FC 2.0
CC not tested
pH 7.0
TA 190
CH 275
CYA 70

Here is a pic from the first day I was able to open the cover.


We had this pool built last year and I knew jack about pools. I absolutely hated walking into the pool store and the dirty feeling when I left.

This site has helped me understand the chem I forgot, thank you! So far I like the Pool Math app.

 

[duraleigh]

Welcome to the forum

What is your TA?

 

[triptyx]

The pH rise you'll see is entirely dependent on your pool size and how much aeration you're able to apply. My tiny pool that is around 1/5th the volume of yours takes about 6-8 hours to go from 7.0 to 7.6 with the spa jets running full blast and the spa spillway glugging into the pool. So getting that rise to happen may take a bit of patience unfortunately.

 

[Richard320]

I just plugged your numbers in, and you're at no risk of scaling, so why obsess over the TA?

Driving the pH so low is pretty risky. You could damage the heat exchanger in the heater.

From Maintain your chemicals correctly

New heat exchanger

Low pH damage

As it says in the Lowering TA article: You shouldn't lower TA just to reach a target number. Make sure you actually have one of the above issues before lowering your TA.

 

[AftonJeeper]

Welcome to the forum

What is your TA?

Thanks, 190

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The pH rise you'll see is entirely dependent on your pool size and how much aeration you're able to apply. My tiny pool that is around 1/5th the volume of yours takes about 6-8 hours to go from 7.0 to 7.6 with the spa jets running full blast and the spa spillway glugging into the pool. So getting that rise to happen may take a bit of patience unfortunately.

Perfect, Kind of what I was hoping to learn. Maybe I build more bubblers...

- - - Updated - - -

I just plugged your numbers in, and you're at no risk of scaling, so why obsess over the TA?

Driving the pH so low is pretty risky. You could damage the heat exchanger in the heater.

Where did you plug them in? The app suggest to be between 50 and 90. Is it wrong?

I'm trying to move pH up not down, hense the bubblers and waterfall and not adding acid since it dropped below 7.

 

[duraleigh]

Yeah, just keep at it. triptyx is on the money.....it'll just take some time......no rush unless you get tired of listening to that compressor.

 

[triptyx]

Thanks, 190

Where did you plug them in? The app suggest to be between 50 and 90. Is it wrong?

I'm trying to move pH up not down, hense the bubblers and waterfall and not adding acid since it dropped below 7.

You can use PoolMath (link at the top of the site) to put in all of your numbers. Once they're all filled in, you'll be provided with a CSI value. This is the "Calcium Scaling Index". Some of us use that index to determine how prone to scaling, or acid damage our pools are. Richard plugged in your numbers and determined that at the moment, you're not at risk for scaling, even with a TA that high. That said, as the water warms up, you'll find that number rises.

There is no real "suggested" value for TA - it's what I call a magic number - it's different for everyone based on their needs. 190 is a bit high, and you may find you need to use a lot of acid to keep pH rise under control (maybe not, depending on your fill water). Some of us run TA at 50-60, some run 100 - it really depends on your pool and how it acts at different TA values.

With regards to adding acid to bring TA down - since your pool is coming up so slowly, you may want to target 7.2 for your acid adds while lowering TA to protect your equipment. Once you are satisfied with where your TA is, you can dose the pool for 7.6 - no need to bring pH down to 7.2 every time you add acid.

 

[Richard320]

Where did you plug them in? The app suggest to be between 50 and 90. Is it wrong?

I'm trying to move pH up not down, hense the bubblers and waterfall and not adding acid since it dropped below 7.

I don't have a smartphone, so I don't know what the app looks like, but on a web browser, poolmath shows target (bleach/vinyl/TFP) to be 50-90+. That means if you're below 50, you pick a target somewhere between 50 and 90 and it will tell you how much baking soda to add. The wide range shows it's not critical. If you target 70 and it asks for 3.6 lbs, it's easiest to just add 4 lbs and throw away the empty boxes. If you're anywhere above that, you just plug in your current value as the target and nothing is needed.

If you're relying on that poolfrog to chlorinate, that's trichlor (and metals) and the recommendation for TA is 100-120+ due to its acidity.

TA is only critical if you're at risk of scaling or etching plaster (CSI value) or if the pH climbs so fast you need to add acid every day.

 

[triptyx]

Richard just made a very important point - if you're using trichlor or dichlor (hockey pucks) and not bleach to chlorinate, the acidity of those chemicals is fighting your attempts to raise pH. I can actually lower pH in my pool by using chlorine pucks. Pull out all of the solid chlorine and use bleach to chlorinate instead and I think you'll see your pH come up faster with the aeration.

I'll add that your CYA is already very high at 70 and will require a partial drain of your pool to bring down - you're going to want to switch to bleach or liquid chlorine anyways to prevent CYA from getting even higher. At 70 CYA, you want your chlorine at 8-10ppm, and NEVER lower than 5ppm (you're at 2 right now). Letting it fall below 5 risks a green pool full of algae.

 

[AftonJeeper]

Thank you all for the info. Need to decide if I use up the last 3 pool frog chlorine thingys or toss them. Maybe I'll keep them as a back up for any vacations we might take.

I did drain and replace a few thousand gallons last night because of the CYA reading. Before I had a real test kit my strips where telling me I had none.

One tip I have for those on well water you can use hole house filters with carbon filters in them to remove most of the junk we pump out of the earth. I was told by my well company to run as many hoses as possible when filling. Ideally you do not want the well pump to shut off. 55 degree water will keep it plenty cool, the constant cycling on and off is what would kill it.

My water was perfectly clear when I first filled my pool, my dog's water dish has a red stain on it.

You can use PoolMath (link at the top of the site) to put in all of your numbers. Once they're all filled in, you'll be provided with a CSI value. This is the "Calcium Scaling Index". Some of us use that index to determine how prone to scaling, or acid damage our pools are. Richard plugged in your numbers and determined that at the moment, you're not at risk for scaling, even with a TA that high. That said, as the water warms up, you'll find that number rises.

I thought CSI was a TV show...

 

[triptyx]

hehe!

Personally, I'd put the pool frog cartridges in the trash if I couldn't sell them to some other sucker. The main problem with them is that they add metals to your water that can cause staining. If you're going to use pucks for vacation, I'd recommend getting some regular old dichlor or trichlor pucks and a floater. Avoid any pucks that have "Blue" or "Xtra Blue" or "Algae Killing Formula" on them - these often contain copper or other metals.